Tatum's only overhyped by the kinds of good loyal green glasses C's fans who think he'll be the best player in the league in 2-3 years or that he's too good to trade straight up for Anthony Davis. Full disclosure: I think the first one's not impossible but highly unlikely and am kinda sorta in the 2nd camp in spite of my brain knowing better.
Other than that he's pretty accurately hyped - incredibly talented rookie, superstar potential, high skills, size, and athleticism, showed he can thrive under playoff pressure. About as promising as any rookie's ever been that wasn't a superstar already.
It is fair to say his shooting's more likely to regress than not, but that's just because the numbers were so strong to begin with. And it's fair to say he still has flaws, and that nobody's guaranteed to become a superstar until they do it, but after the playoff run he's earned the buzz that comes with being a "name" player, just like Mitchell has and Simmons hasn't.
Oh and the article's junk, of course. But the basic argument is an interesting one - what's an accurate hype level?