I have not seen this stated by ST staff anywhere: do you have a link? All I’ve seen is that Edge is still in development and transition details will be provided in the future.
For example:
I’ve also seen it said that custom DTHs will not be automatically converted to edge drivers. You can delete the device and re-add it and it should pick up a stock Edge Driver if there is one that matches the fingerprint, but that’s not the same thing.
So I think we just don’t know yet what the transition process will be. But maybe I missed something. 