Why isn't Spiritual Antithesis YMMV when Spiritual Successor is?

This is one of the bigger discrepancies I've seen in two tropes that are clearly two sides of the same coin. Spiritual Successor has the YMMV banner at the top of its page, while Spiritual Antithesis doesn't, and as such I sometimes see Antithesis on Main while YMMV has a Successor bullet (since the two aren't mutually exclusive), like Priscilla and YMMV.Priscilla. Both are Audience Reaction tropes, shouldn't they both be YMMV?

Because Spiritual Antithesis hasn't had TRS yet.

I think the difference is that Spiritual Antithesis is done on purpose, while Spiritual Successor is an association fans make.

"A polar opposite of the Spiritual Successor, the Spiritual Antithesis is (intentionally or not) referencing or invoking an earlier work by using similar characters and themes, but going in a completely different direction"

Emphasis mine