I mean unless he outright says so, any possible answers can only be speculative. Also there's a good chance that this has nothing to do with U.S. internal politics, but is a reaction to Russian war efforts.
For example since Western countries have, for a long time restricted the usage of their weaponry for purposes within Ukraine, Russia changed it's strategy and often launched attacks from Russian territory so that they became increasingly hard to defend against without being able to strike the aggressor. Hence Biden has already permitted Ukraine to attack some targets within Russia.
Since then Ukraine has taken some land in the Kursk region, while Russia has apparently recently gathered large amounts of North Korean troops within it's borders, that apparently already attack Ukrainian (and depending on the source also Russian targets...). So Ukraine has for a long time argued that they need those kinds of weapons and that they are effectively fighting with one hand behind their back.
So rather than a "surprising", "early inauguration present" for Trump, that might be a long discussed reaction to a changing situation that has nothing to do with U.S. internal politics and people might just have not been paying as much attention to that conflict as the president and his advisors (kinda is also part of their job).
Also depending on whom you ask that is somewhere between a threat leading directly to WWIII or "too little too late".
Like apparently the ATACMS are actually to short in range to strike against Russian-fired glide bombs. Though argue that even just the ability to make a few deeper strikes would require Russia to react and disperse their troops making it at least a little harder.
Edit:
Ukrainian President Volodymyr Zelenskyy was in the U.S. back in September, he presented President Joe Biden with a list of targets that he wanted to hit. Biden didn't refuse the request outright. Effectively, they agreed to keep discussing it. Finally, though, that decision was made to grant Ukraine this long-standing request, to allow them to use these long-range missiles deeper inside Russia. At least part of the reason for the rather abrupt policy change here is that the U.S. viewed the deployment of North Korean troops to Russia. Thousands of them, in fact, as an escalation, one that merited some sort of response. So, this, at least in theory, is part of that response granting source
So North Korean troops were indeed cited as the reason.