Yes - the migration is underway now and ST is slowly converting existing devices. The only devices I’ve seen reported here as automatically migrated, or observed myself so far are ST buttons and Z-wave repeaters.
If you’re currently using stock DTH (have not installed custom code), your devices will eventually convert to stock Edge drivers. If it goes smoothly you’ll never notice a difference.
If you want your switches to use this driver after migration, you can enroll using the “Channel Invitation” link in the first post and install the driver(s) for your devices. If you do it before those devices are migrated, and if the fingerprint for the device matches the one in the driver, the driver should be automatically selected (priority over stock driver). If you install it later, or the preferred driver isn’t chosen during migration, you can change the driver from the three-dot menu on the device screen.
Details about migration are here; the migration is part of the first stage but it seems like they’re only now really starting to move devices on a wider basis.