Indeed, Boleslaw the Brave conquests should be possible due to game granularity. Rehabilitating German empire borders, which are historical borders too, wouldn't massacre anything, it's literally just a change of some pixels and a lot of people will want to achieve that look; in fact, it's made less fun right now because they cannot be replicated.
This is not an attack on the people who now live in these regions. Following this logic, no Paradox game should exist because it could be offensive to the whole planet because their modern homeland look somewhat altered and it simulates historical tragic events.
And this is ironic because I got confronted in the past when I asked if Project Caesar was aiming for simulating history, and no, they said PC should be a
historical sandbox. Victoria 3 was also said not to be a world conquest game, and... people do it anyways