Not surprising since the film isn't going to be out for another 22 months.
On average most films have about 18 months from preproduction to release (there are variations of course, but as a rough average 18 months is most common) so nothing is even likely to start until next year.
The people involved all have other projects as well.
'If the Apocalypse starts, beep me!' - Buffy Summers
'The sky's the limit.....' Jean-Luc Picard, 'All Good Things'
courtesy of Saquist