I can't think of any company that could publish a wrestling game that would be any good...who makes the Mortal Kombat games? Did Williams go out of business/change their name/get bought out/merge? Because the only contenders I could see making a decent game would have already made one by now (Capcom, mostly, and they already made Saturday Night Slam Masters).
Maybe IGN just forgot about Slammasters. It wasn't the biggest thing ever really.