I've uploaded a signed version of the package that you can try: https://www.dropbox.com/scl/fi/3bh647k44e4v7kkpi9nke/MIT-App-Inventor-Support-Tools-Intel-Signed.pkg?rlkey=yiw1kjl2quhkbxhxbm6d2j5bl&st=9e93mkd2&dl=0
Hi! Thanks for this. Too nervous to try to download anything from dropbox .... I mean, I do believe you are you .. but, it is not from the main site is it 
When will the main webpage be accurate? Is the phone companion working fine?