Actually Romanian had always used Cyrillic until it switched to Latin in late 1800s to stress its "Latin" origin. I think Moldovan just stuck to it being a Russian province even before the Soviets, though I am not sure of what happened there when it was part of Romania in the Interwar period.
I think the Poles would not be happy AT ALL with being forced to switch to Cyrillic.
As a sidenote, IOTL the Soviets never tried to replace the Latin script in the Baltics either.
Really? Wow, you learn something new every day.
BTW, I love your sig