Yes, Huber has nothing to gain financially.
At the same time, the video where he sees Shenmue 3 and breaks down into tears has like 2 million views on YouTube combined.
People will naturally think there is a bias there.
If it's only because of bias because he's a fan of Shenmue, then almost nobody can review sequels or games connected to specific companies any more. It happens all the time, especially with long running series or series which are generally well reviewed (eg. Zelda or Mario). Hell, even some big names in the industry have a lot of fans which can cause people to review a game differently because of that (eg. Kojima or Ueda come to mind, but there are plenty of others).
A professional reviewer is able to set all those feelings aside for the most part and tries to review a game as unbiased as possible.
There will always be some bias when people review something (even if someone likes a specific genre or not makes a difference) as that's just human nature, but it shouldn't make a big difference as long as it's an honest reviewer reviewing the game or movie or whatever.
Jones isn't allowed to review Rockstar games or openworld games anymore?
And almost nobody in the world can review the FF VII remake since FF VII is so beloved?
I'm sure Huber is able to honestly review the game. He can also preface the review if needed so people know he has backed the kickstarter (I don't see a difference with someone buying a game and then reviewing that game). They can then decide for themselves if they want to "trust" the review or not.
It's always best to watch or read reviews from people you more-or-less know their gaming preferences off anyway.
If Huber can't review Shenmue 3 because he's a big fan, Brad can't review the FF VII remake either imo (and probably nobody at EZA can, except for Jones).
That would just be silly. If people are that concerned with stuff like this, it's probably best that they stop reading or watching reviews as there is always some minor bias in one way or another.
That being said, I do understand if Huber decides not to review Shenmue 3. I personally don't think backing a kickstarter is a problem, but I understand why it wouldn't feel right.
In the end, a don't skip or impressions video is just as valuable as a review. The only difference is that there isn't an official score (which is just a number anyway). So even though I don't see a problem with having him review the game, it might be for the best to just do a don't skip or impressions video instead (even though it's silly that this needs to be discussed at all).