IDW why anyone keeping up with the production would be shocked by Ezra filming FB3 before Flash, FB was suppose to start recently but got delayed till early next year, it's like a well known facts on twitter.
Did the same people think Ezra should have shot Flash right now when FB3 was delayed, and IT director was in charge for how long? like 4 weeks? after he finished the press tour for IT2?
Dude needs at least a year to get the script and production in order before shooting, unless Ezra packs his schedule for the entire 2020 and none of it is called Flash, otherwise the normal scheduling right now is -
Ezra to film FB3 until around mid year, IT director gets his ducks in a row, they get to work together on set from the second half of the year, hopefully finish filming early 2021, get through extended post production for a 2022 summer release, which would be less than 3 years since IT2 came out, and that is standard timeframe for a director, might even be quick considering Flash will be CGI heavy.