As long as we don't excuse rushed writing with subjectivity
I still think they already had the story, if not more for 25 when they shot 24. Wasn't there rumours at some point that 24&25 would be shot back to back? Obviously they didn't, but if there was any truth to those rumours, then it means they'd already worked on 25 at that point, which in turn suggests 25 is a continuation of 24's story (which would likely be a hybrid of OHMSS and YOLT).
So maybe the recent hiring of P&W was to finish, or doctor that existing piece of work. With Craig (apparently) on board it's all systems go on that script and IF that were all true, then it would mean that P&W were hired because Craig had just signed up, making that existing script viable.