Instead of counting calories, exercise/high protein?

Anything above & beyond your maintenance calories would add fat or fat + muscle. Not pure muscle.

Just curious, what if instead of counting calories in maintenance, if you just ate reasonably healthy, but made sure to eat high protein and exercised (cardio/weights) consistently, would anything you eat above your caloric goal simply add muscle instead of fat?

If you eat at a calorie surplus you will gain fat, that's unavoidable. That's why body builders have a bulking and cutting phase.

When your bulking, the goal is to eat at a calorie surplus and gain some weight. This is ok because you are also heavy lifting so you will gain muscle. The downside is that with any calorie surplus you will also gain additional fat. You cannot grow muscle mass while eating at a calorie deficit, which is why they bulk.

When your cutting, the goal is to lose some of the fat you gained while bulking and you want to still heavy lift to mitigate muscle loss while eating at a calorie deficit.

OP, my recommendation is to keep calorie counting. You were at a higher weight before because you weren't, you will more than likely start going back into bad habits if you stop. If you are now at your goal weight, why not consider a heavy lifting program and try and put on some muscle mass. Being at your goal weight is ok and all, but you'll love how you look if you were to put on some muscle.

It's always a mix of muscle/fat, unless you don't exercise then it would be just fat.