Last that was heard from Mazda's CEO about this was that the launch of the new RWD platform had been pushed back to 2023 (assumed to mean 2023 model year). IIRC, they decided they needed more development time to design a platform better suited to future hybrid/EV drivetrains, as well as the new longitudinal gas/mild-hybrid and diesel engines already planned (which BTW very probably means new transmission(s) too, so I'm counting on at least an 8-spd auto next time around).
From what I've read, both outright and speculative (plus reading "between the lines"), I think the most likely scenario for the SUV line in North America will be all new RWD biased CX-50 and CX-90 replacing the CX-5 and CX-9, respectively, as 2023 MY's.
And while things certainly could have changed, Mazda was pretty clear when the CX-4 was introduced for China that it will not be offered (implied "ever") in other markets. It appears to me the CX-30 was/is our surrogate.
I'm guessing the CX-30 will continue on the current FWD platform into the foreseeable future. And I'm betting we won't even see a facelift until the 2024 MY, due to resources being allocated to CX-50 & CX-90 development in the meantime. I do wonder about the fate of the CX-3 though. Hard to guess on that, but maybe a revamped version appears as a CX-10 or CX-20 at some point - or they might decide it no longer fits the new "premium" image - ???
I'm sure Mazda has reserved all the badging permutations for possible use down the road, but personally I'd find it unlikely to see something like a "CX-70" wedged between the CX-50 and CX-90 in the US/Canada market unless and until the brand makes some great leaps forward in total sales volume here.
Just my 2¢... and worth every penny you paid for it!