What happens to 1.0 avatars after 30th March, 2025?

Hi.  Meta has said that after March 30, 2025,  both the Avatar 1.0 editor flow and Meta Avatars SDK prior to v29.6 will no longer be supported.  I'm not sure what the practical impact of this will be.  Will 1.0 Avatars simply no longer load in games if the upgrade isn't done or will it simply not be possible to edit them?  Some developers have already upgraded, but there are a lot of games where the 1.0 Avatars are still being used.