The only bulwark between the Baltics and Putin is NATO and the US.. Trump LOVES Putin and wants to dismantle NATO.. So, I'd say, YES.. The Baltic states NEED to worry.
I believe they've been on alert since the middle of last year when Trump was only a bad joke. They considered the NATO forces on their soil were inadequate to deter Russia. With Trump's stated intention to build a wall and draw up his drawbridge then, you're right, they have even more reason to worry now.
Yes... The"Russification" that's taken place there since the end of ww2 seems to put them all in the same category as the eastern states of the Ukraine.... And we know how that turned out