Apple's phones have, for several years now, been on a tick/tock sort of pattern. iPhone N Pro has the new CPU (15 Pro got the A17) and iPhone N uses the prior gen pro CPU (15 got the A16, which was in the iPhone 14 Pro). So this is probably an A17+ feature. If they stick to form, the iPhone 16 will have the A17 processor and the iPhone 16 Pro will have the A18.
That's part of the differentiation between (on the phones) the Pro and non-Pro these days with the Pro getting all the new stuff, and non-Pro getting a partially improved (and partially degraded, usually wrt the camera) Pro from the prior year.
Actually 15 Pro has the A17 “Pro” SoC, while the regular 15 uses the last gen A16 Bionic (Bionic being the regular version). We don’t know whether the next regular iPhone will get the last-gen A17 Pro (which would be a little confusing), or a “last-gen-but-new” A17 Bionic or if they’ll go with 18 Bionic + Pro.
I assume it will come to all the iPhone 16’s this fall? Or is Apple Intelligence a Pro Feature?
Either way, my first reaction is that this is going to sell a lot of iPhones.