“Russia might attempt to annex Transnistria around Feb 28th”
They could take advantage of the absence of American support, causing everyone else to fail to challenge it.
As I've mentioned before, the Dniester is the historical border of southwest Ukraine. I would not be surprised if Chisinau was willing to cede Transnistria to Kyiv after the war. First, to allow Moldova to join the EU without resistance from Transnistria. Second, because Transnistria has historical ethnic, cultural and economic ties with Ukraine. Russia annexing the territory would mean Ukraine could only take it in war. This might be Russia's primary reason for annexing.
They could take advantage of the absence of American support, causing everyone else to fail to challenge it.
In the short term, it would be a simple vote, a referendum in Transnistria, then formal annexation by Russia. If they thought they could pull it off, they would already have made amphibious landings west of Odesa to establish a beach head into Transnistria. That ship has sailed sunk.
In the longer term, Transnistria becomes another massively armed garrison exclave akin to Kaliningrad, to be used in future wars against Ukraine, Moldova and beyond.