Hopefully they'll update the Macbook 12". I'm in need of replacing my Macbook Air 13" 2012 model.
I'm in a similar scenario (with a late 2010 MBA), but, however, I feel there's no successor for the 13'' MBA which would really tempt me. My 13'' MBA weighs 1.3 Kg. It's been 6 years from that, so I'd expect that I could buy a display bigger than 13'' with a weight of 1.3 Kg, or at least that a 13'' display would be lighter than 1.3 Kg.
But the only options are either the 12'' MB (yes, only 1 Kg but you lose 1 inch of display), or the 13'' MBP (which has the same weight as my MBA, but has no magsafe, no standard USB, and no CUDA-compatible GPU -my MBA has an NVIDIA GPU that can run CUDA code).
I'd really love a 15'' MB (if the 12'' MB has a weight of 1 Kg, I guess a 15'' MB could have a weight very similar to my 13'' MBA, and that would be a really worthy purchase).
Alternatively, if they add an NVIDIA GPU to the next 15'' MBP, I could consider it interesting even if it's not as light as my MBA, because it would allow me to write and debug CUDA code.