Not any cats, but those who're already accustomed to the outdoors. I've been to multiple animal shelters in Germany over the years, all of them had information about if a cat required access to the outdoors to be happy. And that was a requirement for adoption of those cats. You can see it here for example at the Hamburg shelter Süderstraße, the biggest one in the city. Every cat or group of cats has the "Haltungsanforderung" (adoption requirements) mentioned, most of them "Freigang" ("Freeroam") since they often receive strays and there're less people in the city who can provide that.

I've no clue where the hell you all live or how big your houses usually are, but despite the known heavoc freeroaming cats can cause: if they are freeroamers then, according to the professionals at the shelters I spoke with, suddenly keeping them in an average apartment (i.e. ~60m²) would be almost abuse and they will not let you adopt a cat if the cats individual requirements aren't met.

And to be clear once more, the shelters don't advocate for everyone to let their cats out. They advocate and educate so people won't do it in the first place, BUT if a cat already knows the outside and would go mad inside they respect the animals' requirements.