why would scarle only post this on her membership? why not twitter or just a regular community post?

because niji is getting a bit smarter. they realize they can't terminate a liver after maintaining radio silence for weeks. so they're just going to impersonate her, pretend that she's "sick" and constantly delaying stream, keeping most people (except her members) in the dark to pipe down the yab.

and then force her to resign due to "medical conditions."

don't believe me? look at the word "ok." In every previous Scarle posts, she always used "oki" or "okie." Emojis and everything else looks fine... but a writing habit like that being randomly different should already set off some alarm bells