Its probably not so much about this upcoming game or cheating to beat the Bengals
IMO it's more about building a database on Zach Taylor. Tendencies. Interactions with players and coaches. Maybe signals. Probably useless but you never know. The information will be banked and could be useful 2-3 years from now.
Think about it: Taylor could be OC for a real team in a year or two. Either way it's info on a guy from the McVay coaching tree.
Belichick thinks in 4D while most NFL coaches want to tell loud and have guys run through brick walls.