I'm not aware of any such limitation on Android. And if there were, why would UnionPay take the time to develop an NFC payment option on their Android app?

That said, so far as I can gather, when it comes to Visa/MC your only NFC option on Android is through Google Pay (unless you have a Samsung phone, which has its own payment option). But this isn't a technical limitation, so far as I know. The UnionPay app certainly recognizes my phone as NFC enabled.

In any event, I refuse to use Google Pay since Google already has enough information on me; I'm not going to let them add my shopping to their dossier.