Starting to … ? Always has been! Even FSX / P3D used simple 10 day of slightly varying sky color to convey the sense of actually being in a slightly-changing sky.
MSFS tries to be super clever with quantum-level computations (going from the slide decks when they introduced atmospherics) of things like smog particles yet completely fails to utilize any of the troves of data available to produce anything remotely better than what we had in last 10 years or more! And don’t get me started on that night-time skybox 
…
I guess this is so all the marketing shots have ‘sameness’ on Xbox and PC, but its the most disappointing part of the experience for me - ‘The SKY is calling’ is the tag line… but the SKY is BORING!!