I was surprised there hasn't been a drivers rating update, but i'm thinking they'll do one around the end of each podium pass so there'll be 3 or 4 (as the season ends in december and therefore ratings won't change for the passes beyond that when nobody is racing)
In terms of the cars, last years wasn't too off immediately so I think it was quite early. This one is abit more fine-tuning so I'd expect to see it during the August mid-season break window. It's usually a one-and-done so I think they'll delay it so they know they've got it right.
Currently though, it's working for me. I have Red Bull and McLaren mostly trading wins. Ferrari have lopped with a few (like 3 out of 19) but are consistently podiums and Russell has a win and a fair few podiums. The lower points battle is tight where all the other teams have scored, and look like scoring, points with nobody way off the back (except my team.. and Hadjar). I accept that it's not especially reality but it's made the game interesting so i'm in no particular hurry!