It takes 3 to 4 months to complete a comic. This means that issue # 597 is probably ready, with 3 issues remaining to complete the storyline.
What Tom Brevoort usually does in these cases, is to call someone to rescript issues and write the end of storylines, avoiding dangling plots for the future writer.
Let's see if we will have any news about this, when Marvel and specifically Brevoort, recover from the unpleasant surprise. Unpleasant for them, but very pleasant for us.
The sort of writers used in these emergency fill-in issues tend to be really, really, really, reeeeally bad.