Same issue here. Banned by Whatsapp right after getting a new simcard and changing phone number. I don't know if I'm unbanned or not, but now I get this message about using the official app when I try to register again.
Of course, WhatsApp support and ban appeals are completely useless, as is the norm for this kind of hateful big tech company. The best solution would be not to use that shitty app at all, but a lot of other people only use that.