Could your sources have been referring to the Euthyroid condition? I believe that is what they call it when you are being effectively treated for Graves’ and not showing the symptoms of the disease, but not in remission either. I’m certainly not an expert, but I’ve been around long enough to know a little (much more than I ever dreamed I would) My daughter was on Tapazole for 2 years, euthyroid very briefly, and now back to the hyper stage. Remission for us, if ever actually achieved, was fleeting good luck!!