Although I would personally argue Germany is not yet in the same boat as France & Sweden.
I agree. At the moment when it suits them, German ``elite`` would use even `migrant situation` in order to deepen cohesive forces of its germanized populace (former Slavic/ie Sarmatian people that is gradually assimilated). Ground would prepare indoctrination with absolutist ideologies, as always. Then, eventually, in a single `Crystal night`, populace would ``get signal`` to destroy non-desirable ethnic factors in Germany.
None of these seem possible in Poland anytime soon.
Poland needs to accept healthy level of multiculturalism and look on example of former Yugoslavia (Serbia) in this regard. Yugoslavia was (Serbia still) able to exist as leading Non-Aligned movement country and still to preserve its own values. It was (is) achieved by willingness to accept, for example, African students but, very few of them got right to after studies stay in Yugoslavia. That way, Yugoslavia was helping to third world countries, was exposed to multiculturalism in return and avoided to be ``massively`` populated by foreign factor.
Factor that may bring `healthy level` of multiculturalism in Poland is exactly Intermarium, considering internal migrations within confederation and considering Intermarium`s, let`s say, image of friendly country that is willing to support development of less advanced countries.