Once the Migration Tool goes live, it will migrate Routines to Scenes+Automations and SHM to STHM. Note that the migration tool is one-way. Meaning after it has migrated your Routines and SHM, you will no longer be able to create/view/edit the legacy Routines or SHM. (You'll have to use Scenes or STHM) This has implications if you are using community apps like SharpTools, ActionTiles, or WebCoRE as you'll lose support for controlling your Routines and SHM. There are workarounds for controlling Scenes and STHM via virtual switches or location modes, but it's something to be aware of.