Amazingly, I can't find anything even close to definitive on this across multiple google searches and phrasings.
A Circle of the Moon druid casts polymorph on themselves for some of that sweet, sweet, Giant Ape combat action. Does the Primal Strike class feature still function? Exact wording from the PHB (dunno if there's errata about this) says this:
Starting at 6th level, your attacks in beast form count as magical for the [blah blah blah]…"
It doesn't specify "While Wild Shaped…" or anything similar, and as mentioned, I haven't been able to find even a similar topic discussing their intersection.
Best Answer
No, polymorph replaces all class features including primal strike
The description for polymorph says:
So literally everything about your character is replaced by the statistics of the creature you polymorphed into (except alignment and personality). Class features are included in that.
Essentially, when you are polymorphed, you completely put away your character sheet and you use only what you see in the creature's stat block. If you don't see it in the stat block you cannot use it.
Jeremy Crawford has confirmed this as well:
Thus, since primal strike is a class feature, you cannot use it while polymorphed.