>>5427095Since no one actually answered your question, i will.
Everything is canon, and most stories are in their own parallel timelines, all of them are canon though.
You can argue that prisma illya isnt exactly canon, because Nasu doesnt supervise it.
But Fate/apocrypha, fate/extra, Fate/Grand Order, Kara no Kyoukai, Fate/Strange Fake are 100% canon.
Whoever said something "stopped" being canon is a fucking moron.