We don't.
What we do know is that Gurman, after the M1 was released, got the M1 Pro, M1 Max and M1 Ultra right, but wrongly predicted the M1 Extreme. My guess is the latter was at one point planned, but canceled long before any of those shipped.
One thing we don't know is if the M2 Pro, etc. will even be a thing. The A14 was announced in September 2020, the M1 in November (2 months), the M1 Pro/Max in October 2021 (13 months), and the M1 Ultra in March 2022 (18 months). The A15 was announced in September 2021, and the M1 in June 2022 (already 9 months). The A16 is probably something like 6 weeks away, and will likely bring a process shrink.
For the M2, where efficiency plays a greater role (MacBook Air), the A15 was worth it: the Avalanche bump is relatively minor for 19 months, but the Blizzard (e-core) bump was significant, leading to improved battery life, and as a bonus, the GPU has improved a fair amount as well.
But for the pro Macs (MBP, Studio, MP), I think a more significant upgrade is needed.
We haven't really seen yet how Apple thinks about the cadence of their Mac chips. Was M1 to M2 (19 months) an outlier for supply constraint reasons, or is that roughly what they're shooting for?