I participated quite a bit in r/whatsthisbug and r/spiders helping identify bugs (mostly spiders) for people. It was something I really liked doing, especially educating people about how spiders aren't things to worry about. Guess I'll just head back to iNaturalist for that content.
Other than that, more niche gaming communities were a big one for me. r/puzzleanddragons is a mobile game I play often and the sub was super helpful for news and game discussion/guides. I hope it can kick off here.
I think consent is the most important discussion here. The people that continue to profit (monetarily or otherwise) off dead creators are often looked down upon, eg. Brian Herbert's Dune continuation, Stephen Hillenberg's death and continuation of spongebob (and it's spin offs), etc. Terry Pratchett had in his will to use a steamroller to destroy all his unfinished works as he knew if not they would likely be used to profit after his death without him.
I'm a proponent of the recent advances in machine learning, I use machine learning in my field and I write and use models for hobby level things. I'm also fully a proponent of using these things ethically, and consent here is the most important thing.
If I created a doctored photograph of Robin Williams (even doing something innocuous) that was clearly not something he did and plastered it around the internet it would be in bad taste. If Robin Williams consented to people doing that then sure whatever its nbd. Photographs and recordings should be used with consent, and things like the paparazzi taking non consensual photos are not looked upon as particularly ethical endeavors.