They're too old for this shit. If they go with Shane Black's LW5 idea with old and retired Riggs and Murtaugh forced into one last case though I could fuck with it.
The only way this works is if it's done in one of those "passing the torch" ways, where a new team steps up, and they're mentors. Then again, that might not fly either.
The franchise got the show with Damon Wayans. Best to just let that rock for a while. Don't get greedy.