I don’t think the Bengals actually have concerns, they’re just the test subjects on more restrictive contract language to offset other “fully guaranteed” money they’ve spent on Burrow, Chase, etc.
They’re trying to set a precedent where the league/teams can mitigate certain risk related to fully guaranteed money on rookie contracts, making negotiations down the road “easier” for the guys that turn into real superstars.
You might have a guy get in trouble, fail drug tests, wash out, etc. Instead of paying your superstar quarterback AND that third-year bust their money, you have extra outs on the dude you don’t want anymore if shit goes off the rails.
Other teams will adopt it, if the Bengals find a way to make it work and still get a signature.