I still think MS will announce first, but it's probably not going to be the same day anymore. Sony will have a PS5 reveal event soon, but probably won't give the price (maybe they'll give date though?)
MS will reveal price/date at e3.
Sony will have another event after e3 that reveals price.
That's my current guess anyway. There's always the chance that Sony still have a presentation at the same time as E3 like Nintendo without actually attending, but I don't think they will tbh.
If Microsoft was scheduled to reveal price and date during e3, now that the word is out that Sony is skipping, I bet that Microsoft is now discussing what to do.
It doesn't change your guessing tho, but I think things are much more complicated now.
When PS4 will hit 100m consoles sold: Before Christmas 2019
There were three ravens sat on a tree / They were as blacke as they might be / The one of them said to his mate, Where shall we our breakfast take?