is that cool or imperialistic pinkwashing?

Hardly imperialistic. Sweden’s stance toward Finland and Norway has always been union rather than protectorate. Sweden did hurt its native population in the North and is still not doing a great job on that front, but imperialism is not the word you’re looking for here.

NATO?

Yes indeed, they’re part of NATO now, thanks for highlighting that positive development. Any step that can be taken against the russian dictatorship is a good one.

NATO is still an imperialist tool.

Yes, the aggressive action of too effectively not letting other people invade you. /s