Yeah this Threads issue is getting into the tin foil delusional territory now. Just as you said. They literally say “well use your Instagram acccount” of you bother to read their disclaimers they literally tell you that they are literally using your Instagram account. It’s “Threads by Instagram”. When you first log in it ll import all your Instagram contacts and you cna “follow” them. And if they don’t have it yet it’ll say “you’ll follow as soon as they join threads” there is no “Shadow Threads account, because they are using the Instagram account.”.
You can definitely be against threads and Meta. I Personally am not super thrilled about it. But there is way more than enough to hate a out meta and threads without making stuff up.