If I empty the cavity of stuffing after I cook it thoroughly, and reheat the turkey and stuffing separately the next day, will its consumption be hazardous?
I wouldn't say 'hazardous', but there's additional risk.
You basically need to take the fully cooked bird, and cool it down quickly so it doesn't spend too long in the 'danger zone'. And the same for the stuffing.
Then you have to reheat them back up to a safe temperature ... the stuffing you can add extra liquid to, and make sure it gets up to the necessary temperature, but the turkey itelf is going to be difficult to reheat without drying out (maybe if it were brined it'd be better, but still less than ideal).
I'd say in all, you'd save some time the day of, but the total time spent is going to be much longer, there's an increased risk of food-related illness, and there's an overall lower quality.
If the main interest is in reducing cooking time, I'd start with not stuffing the bird. I'd also make sure that it's well thawed in advance (too many people leave it for the night before). If you really wanted to reduce time, you might be able to butterfly the bird, but it'd then be too wide for most ovens. (maybe do it on two trays?)
If it was fully cooked properly the first time there shouldn't be any problems at all. You may have an issue with reheating the turkey - not that it would be hazardous to your health, just difficult to do without drying it out or burning it. It might be better to fully carve the turkey and then reheat the meat you want to eat instead of trying to reheat the entire thing.