The only real rumors we have right now are that the iPhone is likely delayed until at least October, and that Prosser says there will be some sort of Apple thing happening on 9/8. We have no indication of when other expected hardware (e.g. iPad, Apple Watch) is expected, but an announcement on 9/8 seems likely based on historical event timing, and Prosser's record. Since iPads and Watches rely on iOS 14, Apple won't delay iOS 14 just for the iPhone, because that would hold up hardware sales, and it's in Apple's financial interest to launch hardware as soon as it's available (particularly for the holiday quarter).
One thing that caught me off guard is Apple's iOS 14 microsite says "Coming this Fall", which technically doesn't begin until 9/22. I just don't see why Apple would announce new hardware on 9/8, and wait 2+ weeks to release it, though they did announce the iPhone X on 9/12 and not release it until 11/3, so it's not totally out of the question (especially in a pandemic year). Then again, I think Apple has used "Coming this Fall" before, and usually released it after 9/1 but before the official first day of Fall.
