Depends on how much you think you'd use the features you think the model that hasn't come out yet will have.
The current model didn't lose any of the functionality that made you ready to buy it, so if you can still get a good deal you might be better off with that. Especially if your plan is to only use them a couple years. By then the kinks for whatever new health stuff is coming should be worked out before the newest model when you're ready to replace them.
I just got some cheap noise cancelling TWS buds during a sale last week, but if I start to lose my hearing I'll be thinking about the hearing aid functionality in the Airpods Pro 2 and later, because they'll become a relative bargain. Hopefully they iterate on even more processing and perhaps more frequency bands in the meantime. Wouldn't hurt for them to also add an Android app for the hearing aid stuff at least.