Of course it can. They are simply 2 unrelated concepts. Expressing yourself on reddit was like going into public space, and yelling whatever you had in mind. Doing so on fediverse is the same, but with microphones picking up your yelling to propagate it around the world.
You can have Freedom to express yourself while respecting your privacy: just don’t yell it (i.e. chose a closed private invite only community) or go to som remote forest / desert where there is nobody to hear you yell. Join an invite-only group/room on signal or matrix.
Freedom and Privacy can only exist with common sense.