I think Coach Bill provided a little bit of a "tell" on Mayo's thinking during his (BB) appearance on the McAfee Show yesterday. Paraphrasing, he (BB) indicated that no one should take anything away from preseason because defenses aren't doing anything exotic or disguising, and teams aren't game planning for opposing offenses. All teams are just evaluating basic player skills.
So with regard to Brissett vs. Maye, it's true that Maye has outperformed Brissett in the preseason games. It is also true that Maye still hasn't faced anyone or anything approaching the scale of what he would see if he started in Cincinnati, i.e. minimal game time vs. defensive starters and virtually no experience vs. a game planned defensive scheme.
This is why I think Brissett will start for the first few games... give Maye more time to see how game plans are put together, executed, and what "issues" arise during games that need to be addressed. Throwing him to the wolves on Day 1 just because he can run around a little better than Brissett behind a shaky line isn't going to materially change the outcome of the season.