So yeah there won't be too much change on that front this season. This year is about getting Stafford fully vested and playing fast in this scheme so there won't be any more than the usual pressure on him. Which is to say even with McVay calling the plays Stafford is going to need to make reads at the LOS and improve the offense in anticipating threats.
Down the road I do suspect 9 will be a QB who earns a lot more leeway than we saw with Goff. I think he's going to be an elite QB in this offense. So for me it follows that he will be given more responsibility. But McVay isn't going to risk slowing 9's ability to translate into this offense year one. Thus he'll keep things simple for 2021 IMO.