I won’t claim that Carlson is a Putin Propagandist but if MAGA believes a President Trump will tell Ukraine to go to Hell and they’re on their own, probably not. There are ramifications for him to do such and he knows it
But what he’s likely to try is to pressure Ukraine into giving up something to the Russians in an attempt to end the war. Obviously, that would be unacceptable to the Ukrainians so Trump would then likely blame Ukraine for prolonging the conflict