I didn't see today's fight but can't imagine that it deviated from a typical Beefy performance nearly enough to not make him still a prohibitive underdog against even the current Golovkin.
Golovkin by highlight reel ko. Post prime or not, Golovkin is only gonna lose to a real high level operator, and it's only a couple of those at MW.
You would still favour GGG Smiths style is made for him. But father time is knocking hard on GGG door. If i was Smith i'd gamble on it.