I don’t think that the naming makes sense like that.
For the iPhone chips, they have the family (A) followed by the generation (14) and then sometimes a performance edition (X/Z). This allows them to increment the generation and use the suffix to indicate performance levels.
I could see them doing something like this
M1
Air, Mini, low end MBP
M1t - more RAM, more perf cores, more GPU cores, more ports
MBP, low end iMac
then when then A15 chip is ready, they can do an M version
M2
Air, Mini, low end MBP
(may not ship until 2022)
M2t
MBP, low end iMac
M2s - even more memory, even more cores, discrete GPUs?
Mac Pro, high end iMac
All those letters are just as confusing for non techie consumers as the Intel and AMD model numbers.
To make it simply just use generation and core number.
M1-8
M1-12
M2-12
M2-16
M2-24
etc