When will the cast of Avengers: Secret Wars be announced?

Why don't we have the official cast for Avengers: Secret Wars yet?

The movie has a release date that's a year and four months away and filming is supposed to start in a few weeks but there hasn't been a formal cast announcement. Avengers: Doomsday had one with the announcement of the chairs before going into production.

Generally movies officially announce their casts before any filming begins.

Shouldn't we have that by now? Or is the film being delayed?

That would make sense and explain this, but we haven't heard anything about that either.

What do you think about all this?