There’s one big problem with your point: the erroneous assumption (propagated via Putin’s propaganda machine) that NATO expansion somehow threatens Putin.
In fact, following 9/11 and the years that followed, Putin advocated for joining NATO. Remember, Putin and Bush were buddies and fought together against the “war on terror” in Afghanistan, Iraq, and elsewhere in the Middle East.
Furthermore, Finland has every right to be worried because of the Winter War. If Putin can make revisionist claims toward Ukraine, then he can do that to Finland as well. Actually, it would make complete sense.
Russia under Catherine the Great was an imperial force. A lot of that can be restored in Putin’s eyes.
Thank you for furthering the conversation. It is important to discuss it.