Yes, so right now CTV is a proposed soft fork. It would work with all of the nodes if implemented. TapRoot has already had blocks mined, so it is the continuation of the timechain.

If a new version of Core comes out, and it doesn’t have TapRoot but has CTV, then even though it’s a soft fork of a previous Core version, it is a hard fork from the timechain because it wouldn’t be backwards compatible with the blocks mined with TapRoot transactions.