I mean, he's played in the Top-6, but he's never really been particularly more productive there, than he is on the 4th line. He also just visibly doesn't mesh well with most other Top-6 players. Like...Bo Horvat is really the only true Top-6 Center i've seen Hoglander have any semblance of chemistry with. Probably largely because he also plays a fairly opportunistic, quick-strike game that thrives off the rush and disruption.
There's value in that skillset for sure. It's desirable to have guys in the Bottom-6 who can produce offense there at even strength, from lesser minutes, and without great linemates. But it puts a pretty hard cap on his "upside".
With his age and experience level, he's much closer to a "known quantity" than a lottery ticket at this point. Particularly when it comes to the shortcomings that hold down his "ceiling" offensively. At his age, he's not suddenly going to start seeing the ice massively better, for example. Or get appreciably faster in large areas. It's extremely likely that "he is what he is" and will continue to be a bit of an awkward "offensive Bottom-6 player" who doesn't add anything on Special Teams.