When it was just the writers strike they had to keep going forward but no one was allowed to write gags or improvise gags. Now that the actors are striking the whole production can’t go forward.
There’s a high chance that the two strikes will end together and production will continue without any limitations. We might have the film delayed but I’d rather wait a bit longer for a better film.
The downside is studios will also be more impatient to get the product out the door, so there will be less time allowed overall to finish.