I think this may be a bug in Xcode (or there is something I need to modify in my build settings), but I have a standalone WatchOS app (meaning the only info.plist is for the watch), but I can see when looking into the archive, that although the info.plist inside of the watch product files contains NSMotionUsageDescription, there is another info.plist generated in a higher directory (presumably for an iPhone companion app if there were one for this project), that does not include that. Once I edited this file within the archive, Test Flight took it. Note that I have a few other permissions (e.g., for location) also only in the watch info.plist) which worked fine

I'm also facing this same issue. Set up a watch in family mode (since I don't want all my data on the watch for development), but can't turn on developer mode