I haven't done any of these, so take my suggestions with a grain of salt.

There's always good old email mailing list, though people might not use it due to fear of others (a spouse or child snooping through their email)or use an account they don't check often.

You could build a website or blog people could visit for updates. Just remember to do your due diligence, like setting up a way to filter out underage people.

You could set up a reddit community or discord server where you interact with your fans and automate updates. Again, remember due diligence.

There's always fetlife, I know tons of people upload NSFW stuff, home vids, art, and journals/erotic shorts. People do advertise their only fans and porn films all the time, not sure about the rules of self promotions, though. Hope these ideas help!