the complaint that “Apple is locking USB3.0 to the more expensive iPhone 15 Pro”, despite that being the result of a process they’ve been doing for years now (current gen base models have the previous gen Pro chip).

Are you so sure about this? Perhaps I'm paranoid but I think the "pro" designation on the new A17 just means that it has a USB-3 bandwidth capable memory controller. The iphone 16 will have the A17(non-pro) and will therefore not have USB3 speeds. It's just forward thinking. Apple SOCs have had monikers for years now like 'bionic' and 'fusion', and even the different core clusters like hurricane, zephyr etc.

NONE of them have been featured as prominently in the marketing/press material as the "pro" moniker of the A17. I don't think that's a coincidence, I think the term is more than just a name.

Ultimately, my point is that while you're right that the usage of the A16 in the base iPhone 15 is sufficient reason for it not to have USB3 speeds implemented this year, I wouldn't my breath for next year