I was concerned that it would be disallowed when it went in.
The commentators on NBCSN were outraged by the goal being disallowed. I think it's because they're socialized by the replay rules of the NFL, which can be summarized as that the ref's call on the field should stand in a borderline case. Sigurdsson ticks none of the boxes in the laws of the game that would render him offside rather than in an offside position.
In principle, VAR is supposed to also be letting close decisions like this one stand. In practice, that isn't happening. From what soccer I've seen this year, the refereeing and management of VAR seems more incompetent than corrupt, but I get where you all are coming from on that.