Generally, the vajra master does preparatory retreat with particular pranidhana/aspiration before giving any empowerment. Why cannot those particular videos do benefit if GR has included the recipients of those videos in his aspiration? otherwise he would not say so. Why cannot there be any dependent origination in the aspiration?
What Maclom is saying in this topic is generally acceptable view. Because many aspects of rippening and liberating empowerments are only possible in the presence of the Vajra master.
For an empowerment to have real effect, it is necessary, of
course, that certain external conditions be met. It is also
necessary that the lama who gives it has received authentic
transmission and executes the ceremony with accuracy,
without adding or removing anything. Finally, it is necessary
that disciples who receive it have full confidence in the lama,
some understanding of the process, and conviction in its
efficiency.
source: Secret Buddhism Vajrayana Practice by Kalu Rinpoche
for the latter, the rinpoche's videos definitely do benefit for the particular case.(Unauthorized) people who engage in expounding on and listening
to the tantras will not only fail to receive blessings; they will create
immense demerit from divulging the secrecy of these teachings. A
person who has not obtained empowerment may pretend to practice
the liberating instructions, but, instead of bringing accomplishment,
the practice will create obstacles and countless other defects.
From Tsele Natsok Rangdrol, Empowerment