It all depends on the configuration of the chips -- and note the use of "up to" and less than signs. There are at least plausible leaks of a 124 SM Ampere chip. As I note in the text, that's not a "good" number for the maximum configuration, because GPCs usually all have the same number of SMs. So 16 GPCs with 8 SMs each would work, or 12 GPCs with 10 SMs each (which is fine for the 118 SM leak but doesn't cover the 124 SM leak).
What will the chips actually have enabled, though? My guess is around 112 SMs on an RTX 3080 Ti would make sense. If we use that figure, and the same clockspeed, TFLOPS drops to 25.1. So, that's part one of the story.
The second part is the rumored GA103. I put down 64 SMs as the top configuration, but 72 or even 80 SMs is entirely possible, as noted in the text. So I probably undershot on the GA103 estimate and overshot on the GA100 estimate -- or RTX 3080 and RTX 3080 Ti, if you prefer. I also gave GA103 a higher potential clockspeed advantage. If RTX 3080 ends up with somewhere between 72-80 SMs instead of 64 SMs, performance ends up at 18.4-20.5 TFLOPS.
Realistically, then, RTX 3080 Ti will probably be in the 20-25 TFLOPS range (for FP32). RTX 3080 will end up closer to 14-16 TFLOPS. Or Nvidia does something completely unexpected and the theoretical TFLOPS values end up much lower but real-world performance (ie, the utilization of the available compute) goes up.
Actually, having thought on it a bit more, I think GA103 will probably have more than 64 SMs available. RTX 3080 could still go with 64 SMs enabled, but if Nvidia can do a 128 SM chip, the second tier will probably be much higher than 64. I've adjusted the tables and text slightly to reflect this.