I am all for more options as long as that proposed 13" would be a downsized 14", with XDR and notch, 32GiB, 4TB.... but the old touchbar design needs to go - which I think it will anyways as demand for these models drops and manufacturing ramps down. I don't want to go back to that old darker screen especially, and I am glad I no longer have to use a touchbar either. The base model still comes with 8GiB/250GB to this day which for a "Pro" machine is simply absurd.
(My first Mac with 16GiB was a 2012 MBP... and 10 years later Apple is still pretending less than that is acceptable.)
My dream for Apple's MBP line would be to have a purchasing process where you no longer have to choose between designs and instead you just click on one of three sizes, 12", 14", 16" and then you get presented with the SoC options, M2 fanless, M2 Pro, M2 MAX... that are compatible with the selected size. 4TB option in every model, at least 32GiB in every model, XDR in every model, and so on right down to the 12" option.
I don't think 13" is necessary, it wouldn't be that much smaller and lighter than the 14". 12" on the other hand would be an extremely portable workstation, even with a passively cooled SoC, as long as 32GiB and 4TB are possible there's still a lot that Mac could do. (32GiB should be easy with a further M3 memory bandwidth increase.)