I think the reason for no 7D III is because of the transition to mirrorless, the 7D was released in September 2009, the 7D II in September 2015, so it was do for a refresh in September 2019, and even though, Canon had the M-series, Canon was under pressure to address Sony in the mirrorless market, thus they released the Canon R (5D IV sensor) in September 2018, and the RP (6D II sensor) in March 2019. The R5 and R6 were released during the Covid lockdowns, July 2020 and August 2020 with all the uncertainties and supply chain issues. So the R7 was released in June 2022 with the R10 in July 2022.
Canon still had the DSLR's: 1DX III and 5D IV. So with what was going on, I don't think the 7D III refresh was as high of a priority, everyone I know raves about the 7D II, those customers were happy. If I was a birder, I would have gotten a 7D II, but as a landscape guy, I moved from the 7D to the 5D III and 5DS R. There was talk of Nikon going the way of Sears Roebuck, but the Nikon D800 and D850 DSLR's kept the faithful Nikon shooters with hope, until they hit a home run with the Z9 and later Z8. I think I got the last Nikon APS-C, the D780, which was struggling against the mirrorless environment.
Birders like their APS-C sensors, my first entrance into birds was on Safari last year and for that I have the 200-400 f4 + 1.4x, but it left me coming up short more than I would have liked. I had my R5, R6 & R7 on the trip, but since I was a first time safari, I often had the wrong set up on the river or on game drives trying to balance light and length. Then on a trip to the Amazon, I took my R5, R7 and R3, and exchanged the 200-400 for the 300 2.8 and the 200-800 for length. Unfortunately the AF on the R5 isn't nearly as capable as the R5 II and the folks shooting A1 II, as they could track monkeys moving through the trees, while my R5 and R3 struggled mightily.
I have moved my R7 to my underwater photography niche and was looking forward to the R7 II, or a high MP R3 which is even more of a question mark than the R7 II. I was thinking about converting a R5 or maybe R5 II also, but now I think I am going to go the Sony A7CR or wait on the A7CR II for my FF underwater camera as it affords higher MP's in a smaller housing.
As far as future buyers, I think those in the R50 segment, will probably be more of a candidate for a R10 I/II or R8 I/II. Heck the RP is still selling, long after the R. I think the people that are most enthusiastic about the R7 II are wildlife and to a lesser extent, outdoor sports shooters, they want a premium APS-C flagship, if you ask them , they would really like for it to be a R1 APS-C camera, is Canon going there, highly unlikely, but Canon wants to hold on to that segment, there are plenty of other cameras for new buyers to hop into the brand. How many birders would opt for a R6 I/II over the R7? How many will opt for a R6 III or wait for the R7 II? I am in the wait crowd, as my current travel combo now is the R1 & R5 II.
I am amazed that people have already forgotten the Covid lockdowns and supply chain issues (toilet paper ?). There were a lot of abnormal things occurring, and the current Iran/Strait of Hormuz oil and supply chain issues are probably forcing them to be flexible. Heck, with talk of the market dropping 40-60% here in the US, the camera market may all but dry up.
The reality is that you’re losing over a stop of light with APS-C compared to full frame. Along with the smaller FoV (effective increase in focal length), you get 1.3-stops more noise. So, for example, ISO 3200 on APS-C looks like ISO 8000 on FF.
