While this is correct, it doesn't factor in that most of Poland/eastern Europe's coal electricity generation is sourced from often nearby lignite mines separate from the global commodity system (lignite = brown coal, the dirtiest least, efficient coal type). So the real economic force that will likely have an effect here is the decreasing costs of solar and wind, rather than global commodity price changes as certain markets migrate.

[1] https://en.wikipedia.org/wiki/List_of_mines_in_Poland