So what about Catholic saints who are reported to see visions of the Virgin Mary? Are they false from the Buddhist POV since theism is rejected by Buddhists?
I think the question of when a "vision" is 'true' or 'false' needs to be looked at.
If we are proposing the idea of the object of a vision (Mary, or Buddha or whatever)
as being essentially different from the mind of the person experiencing the vision,
then this would be rejected from a buddhist perspective.
So, like the saying goes, if you meet the Buddha on the road, kill him.
But if one realizes the mind's nature free from obscurations,
then it is no different from a Buddha, even though the vision may appear outside of oneself.
This is because it is only called a 'vision'
when really, it is an expression of the mind's true nature.
It's like shining a flashlight on a wall. The light appear to be on the wall, way over there.
In fact, it is on the wall. But it is also the same light coming from the flashlight, right here.
It isn't two different lights.
This doesn't mean that what Tilopa saw was just all in his imagination.
it means that whatever he saw, that being exists at a level of clarity that is obscured to most people,
like tall skyscrapers that disappear on cloudy days.
I think, the Catholic version is more like the light appearing on the wall
but nobody has a flashlight turned on.
So they call it a 'miracle'.