I’m not saying Poland will annex it, but they may move in the protect the area.
But I think still if Putin installs a government in Kiev, the Western part of Ukraine will break away.
No, Poland is not sending in troops without the explicit invitation from the Ukrainians. Otherwise it will be a PR coup for Putin.
Remember in 1919, Poland secured Kiev for the Ukrainian republic and the Bolsheviks used it as “Poland is threatening Russia again “ and that galvanised the Russians to join the bolshies