I think there may be some difference amongst schools as to what constitutes a arhat. It perhaps must first be qualified as to that we are discussing the same thing.
In Tibetan buddhism arhat is
....(Tib.dgra.bcom.pa/dra-chom-pa): literally "foe destroyer". The culimation of the Hinanyana, it refers to one who has overcome the outward manifestation of the afflicting emotions, but who has not completely uprooted their psychic imprint. Althought free of samsara, an Arhat is not fully enlightened.
The supreme worldly experiences---all the perfect powers, clairvoyance and meditative absorption, and so forth--are achieved through devotion to the Dharmakaya. Obscuration abandonment, cloairvoyance, miracle powers, and so forth--all the qualiteis of Hearer Arhats--are acheived by slight realization of Dharmakaya. Obscuration abandonment. meditative absorption, clairvoyance and so forth---all the qualities of Solitary Realizer Archats---are acheived by partial realization of Dharmakaya. Obscuration abandonment, meditative absorption, clairvoyance, and so forth--all the qualities of bodhisatttvas who attained bhumis---are achieved by greater realization of Dharmakaya. Those bolded are quotes found in (the tibetaan buddhist catachism

)The Jewel Ornament of Liberation by Gampopa, that edition translated by Khenpo Konchog Gyaltsen Rinpoche.
Basically a arhat has removed all the gross manifestations of self in a mindstream but the very subtle annotation of self in the form of very subtle psychic imprint still persists. So total release is not possible.
I disagree with this, claiming that this stated is a predominant view but not the only view available in Tibetan Buddhism..."
Mind never stops (or more correctly the mindstream doesn't end although at the culmination of ultimate enlightenment there is just wisdom)."
I contend and others that hold this view may contend..... that mind is always by its composite origin perceived as a never ending thing that presents as a eternal thing but the actuality may be differing. Any ending or begining would be a ultimate result of circumstantial production. But like water always being wet when it presents.....when presenting it presents as a continum or perceived as eternal.
Circumstances of production may produce a actual eternal presence of a thing, but that is different than stateing that a thing is actually eternal in inherantly existant quality present within it. That is true as well.
As to samsara ending......to end a thing must first have begun. Can we point to a begining of samsara..I'd guess probably not.
We cannot as well point to a minds begining but that may as with samsara point to our lacking ability to perceive truth father than truth or lack of truth being present in a thing.
WE perceive samsara as begining and ending.But is that in the character of samsara or in the character of the thing that perceives samsara..our mind.
I would state it is yes...all in mind.
Samsara for all intents and purposes never exist,s it is illusiionary and thusly can never be found to begin or end. ONly the illusion can begin or end.
Suchly we cannot characterize it in the terms of a thing that can begin or end.
How is this place of no illusion...examine the place before the first and second places of dependent origin, before the twelve links. They present in more substantial form after death and before begining rebirth but do present actually in every single part of what we may call a moment, so they may be examined.....that is how that place of no illusion is. Right before us, but no us may apprehend it, as us is part and parcel of its illusion.
So that is how nosamsara is.....observing will qualify that answer, words conceptually bound, do not.
Too attached to this illusion of self and other.... and we can't begin to look, and will firmly deny the existance of that place, that may be found within ourselves, and yet apart from ourselves. We are but micro bits of our perceived reality. WE will find no aspect of what is found real in us, to be not real in that place, nor what is not really found in us, be found in that place.
In conceptual form I will qualify it as such.....understanding knowing cognicizing is that place and all that we may find in any manner shape or form to exist or not exist in inert or aware form. That is what it is. What draws us away from that understanding is samsara....personal self. Initiated by aversion and attachment.
WE are for all intent and purposes are understanding things. Such is our composite and reality. That which does not understand due to delusion of seperate identity is samsara. So we create the perceived reality that reflects self and other. That is samsara...but it is but self created extreamly complex and filled with nuance and variance as our minds are but illusionary nevertheless in basis(none of this however implies inherantly existant) .
Understanding completely and totally the lack of inherant existance(through tantra, diety, yoga whatever) is the key to attaining full liberation to my personal opinion...but that is another subject. Without a teacher or teaching of formality, and total compassion as intention we cannnot obtain such complete liberation. Self will not be totally eradicated. Enought to prevent the illusion of presentation of samsara but enough to prevent the dichotomy of karma...I'd suppose not. But that is a personal assumption.
So the fate of arhats to my opinion...to either rebirth as bodhisttavas or to remain in pure pure places where they will never accumulate karma or karmic predispostions of action.....to my opinion, or way of thinking.
"This order considers that progress can be achieved more rapidly during a single month of self-transformation through terrifying conditions in rough terrain and in "the abode of harmful forces" than through meditating for a period of three years in towns and monasteries"....Takpo Tashi Namgyal.