I'm involved in 3 campaigns, 2 near the end which will definitely wrap up under the existing rules, and the other will probably find a pausing/downtime point before changing.
In general I think we'll all migrate eventually, but need to actually see the rules and play with them before that happens. I expect a few one shots to help us figure it out.
In terms of your campaign, I'd stick with the existing rules since characters have already been created. If you find a rule you like in the 2024 rules just bring it up at the start of a session. For example maybe you like the new exhaustion rules, just be clear you're using those. Just be sure you're clear on which rules you're using and the players are never surprised by these rules.