That kind of thinking is just going to give countries with nukes free reign to do what they want.. China will be looking at the support that Ukraine is getting and having to question if an invasion of Tiawan is a good idea. Possession of Nukes shouldn't become a free pass to take over other lands without reputations.
China will certainly be doing that.
Let's not forget, the US and NATO countries don't officially even recognise Taiwan as a country and there is limited capacity to support there compared to Ukraine which is connected to several NATO countries with land borders. The likes of Macron have already troed to back away from any potential conflict. It's not a South Korea with any formal alliance to protect it.
My worries here is that China actually fancies it chances and goes for it after seeing the inability of Ukraine to be able to force Russia out even with full backing of NATO.
I don't think China would use nuclear weapons on Taiwan. Or even threaten to.