I don't know if it might have been better if they had invited Abbott, based on his long personal relationship with one of the grooms. It might have thrown the ball in Abbott's court, and forced him to declare his bigotry yet again, even against old friends. Not inviting Abbott so publicly might make the gay couple seem the petty ones in some circles.
At the same time, an invite that Abbott declined could have given him yet another opportunity to spout his homophobic hatred. And played to his Texas base, who'd love him for it.
So I can see a complex game here, almost like chess. Having lived in Texas I can guarantee you that voters would hail Abbott for any snub he offers to gays. The question would be the larger picture in the country. Many of these big-state governors are looking ahead to the White House. They've gotta balance what sells in their home state versus what's likely to sell in the rest of the US.