I agree that $6M on a billion dollar stadium seems pretty trivial. Not going to make or break anything.
The bigger questions is, if they are hesitant about the County's vote, what will happen if they need to put the City's contribution to a vote? The articles suggests that the City must eventually vote on the funds, but that may not be correct.
This news could be an indication that the financing has progressed to the point that other contributions made the $6M superfluous, or on the other hand it could mean that the Governor is concerned that the County would have voted against the funds, and this result would have had far more propaganda impact re "lack of support" than the need for the $6M. In other words, they couldn't afford to have the County vote against the project, so they had to circumvent the County and try to get the money elsewhere. No way to tell from the article itself.