Depends what you mean by "getting away with it".
Mainland China has already complained.
My brother, Monterosa, lives in Taiwan, so I've learnt about the relationship between Taiwan and the mainland. On paper, both sides claim sovereignty over the other, but Taiwan's claim is basically
realpolitik: relinquishing their claim would mean either declaring independence, which could lead to an invasion that they'd have no hope of resisting, or accepting the mainland's sovereignty over them, which would involve giving up a lot of the rights and freedoms their people currently enjoy. I'm sure they'd become a sovereign nation in a heartbeat if Beijing allowed it. So they're in a pretty shitty situation, which I'd like to see change.
I'm not sure Donald Trump is the person to bring about that change, however, and I'm even less sure that circumventing Beijing is the way to do it. Then again, it was only a phone call, hardly a recognition of sovereignty.