Sure, it would be terrific, but let’s not over simplify things. It’s not like some grip maker just needs to kick out typical left & right side panels here and screw them on to a pistol. That’s perhaps the biggest strike against the 3rd Gen — the grip is not only a no-screw atypical one-piece unit that clips in to place, it also incorporates the main spring housing.
A new grip of any sort for a 3rd Gen must be designed to capture the the hammer spring and make it work.
That’s quite a ways outside of simply pinching off a couple grip panels.
You can bet if S&W had went with something more traditional like the 1st/2nd Gens, more makers today would support them. These guns have been out of production now for (arguably) a decade.