from my admittedly limited knowledge on the subject, it doesn't really seem like there's a reason to drop ostatus #nsfw tag on mastodon besides bloat removal. but mastodon isn't a suckless project, a little bloat is fine. pleroma also has this "bloat" to appeal to gnusocial standards.

i think a big problem is pleroma being looked at as gnusocial 2.0 when many services are still going to use gnusocial on ostatus for its GNU connections, and others use services like friendica or diaspora