Doesn't to me. Patreon tier-restricted videos, not to mention family shared videos, fall into this category, and not all creators are savy enough to know they need to do this.
Did they send an email to affected accounts? There seems to be a logical reason for this (newer unlisted videos have a more secure url generator), so I’d say this is neutral at worst.
I received an email from YT about unlisted "playlists", and they even gave me a link which showed me which playlists would be affected. Everything was very clearly laid out in the email.
Some of my videos would be affected and I got an email from them. Seems reasonable to me.
Of course, there is probably a large number of currently unlisted videos from accounts that are no longer active, which would effectively be lost after this change. Unfortunate.
It'd be interesting if Google had made this only apply to accounts that have had activity in, say, the last six months. If an account logs in and was skipped due to inactivity, it would then be appropriate to prompt them for their decision.
That, of course, requires significantly more engineering so I can see why it didn't happen.
