If you watch the fights, you'll see that Gustaf is not just hype. It doesn't matter who's on his record, just watch the way he fights... he's good.
He didn't finish Thiago Silva... so? He dropped him in the first minute then out-maneuvered him all night, beat him up nicely. Thiago dazed him with a hook... so? It was Thiago's only decent attack and Gus handled it well. Then carried on tooling him.
If he loses to Shogun, it doesn't mean he's hype. It means he fought a tried and true hard man with much more experience than himself. Look at the betting lines, Gustaf is actually favorite.