Honestly, I think that is rubbish.
The Bills didn't exercise the option, mostly because of his health concerns, IMO. Then when the New Regime took control, they evaluated contracts/assets/strengths & weaknesses, etc. The double trade (Watkins and Darby) gave them players, and picks, and worked in the direction of their plan. That's not to say I was a fan of each and every move, but at least in retrospect, it looks like they new what they were doing. Every move might not work perfectly, but I'd have to say, so far so good.
Several things happened during the season (Clay going down, Zay not making the impact perhaps expected of him, Matthews missing games, etc.) and WR became a big issue. One thing I like about the coaching staff, so far, is they are willing to make adjustments. Same thing might be true for the GM. Draft choices are assets, and the Bills are in good shape, with those. At this point, KB is a no-brainer deal, especially considering HC and GM are familiar, and comfortable with him.
I don't think there is any doubt Watkins is more talented than Benjamin. But Benjamin could be as productive for them, as Sammy (or close). Plus he was extended, which gives them the extra year at a reasonable price.
BADO makes a good point, as he usually does, saying Watkins and Tyrod had an established connection, and seems to be a better WR for Tyrod's strengths. But I'm not completely sure that can't he changed. Tyrod seems to be able to establish connections with WRs fairly quickly at times, as he did with Thompson a couple weeks ago. If Tyrod continues to roll, scramble and extend plays, he and that big body/jump ball capability of Benjamin could become something of a thing. "Obviously, this is best case scenario." M Marrone