Blk 3 testing of SDD (developmental flight test) is already complete...regardless of the pundits or this idiot.
Blk 4 follow on to commence later this year, early next year missing a relatively smooth transition because the JPO (USG types) couldn't pack their crap into one sack.
So in the meantime, dozens of experienced flight test engineers have either been let go or placed in holding locations in the hopes they'll decide to come back and start rolling again.