I actually think there could be a status match, but it will be like the one with United--largely useless. I could see something like MGM Gold matching to Marriott Gold. Marriott gives gold (and even Platinum) out like candy, so it wouldn't really create a problem for Marriott. It's just a few more points. I could also see Marriott Platinum matching to MGM Gold. That doesn't really give many benefits to the Lifetime Plats or Amex Brilliant Plats who get it easily. MGM Gold is not a strong benefit. I could maybe see Marriott Titanium+ getting matched to MGM Platinum.
The status matching would likely be reciprocated. Meaning if Titanium matches to MGM Platinum, MGM Platinum would match to Titanium. I don't think this will happen. Most likely, the highest status that can be earned is MGM Gold for anyone with Platinum Status or higher and Marriott Platinum for MGM Gold or higher.