I mean, considering Scott is still on for Executive Producing, it isn't like he is completely leaving the project altogether (and I would think that the script would still be the one he wrote with Jade Bartlett).
I do think we need to cool our jets, at-least until we get the word of a new director (which I do think is going to come up extremely quick--as there were character descriptions found by Discussing Film a few hours prior to the announcement).
This is the first for Phase 4, as far as I'm aware. And I mean, Phase 3 had it's own fair share of director changes (Taika wasn't the original director of Thor: Ragnarok folks). I'm more glad that this isn't a Solo situation.