> think Russia would annex a Baltic state

Baltics and Crimea are not comparable. - Crimea has Russia's only warm water port and would never be given up - Russia already has Baltic access (Kaliningrad and StPetersburg) - Crimea has been majority ethnic Russian for centuries and welcomes Russia - Baltics hate Russia

In summary, there is absolutely no logical reason Russia would annex Baltic state.

However, there are plenty reasons why non-Russian interests always repeat this narrative.