I highly doubt that. Like it has been pointed out many times, the almost legendary defensive coordinator John Chavis vouched for Williams. Chavis told Keim and Arians that Williams had bigger potential than both Patrick Peterson and Tyrann Mathieu who Chavis coached while he was at LSU. Obviously, the Cardinals had a direct link to Chavis, but the other teams would definitely have the same information, and Chavis’ words would without a doubt carry a lot of weight to most teams.
Also, the best athletes in college almost always gets drafted, even though they don’t have good stats, and sometimes it even happens in the first- or second round. Just going back as far as I have followed the draft, in 2008 the Raiders took wide receiver Darrius Heyward-Bey out of Maryland in the first round, not because he was very impressive in college but because he was a great athlete. In 2012 the Chiefs selected defensive tackle Dontari Poe out of Memphis in the first round, even though Poe did not put up big stats at Memphis but was an athletic specimen. In 2013 the Bengals selected defensive end Margus Hunt out of SMU in the second round, and Hunt had not posted big numbers in college. In 2014 the Cowboys drafted defensive back Byron Jones out of UConn in the first round though he did not produce a lot in college. There are other examples like the Bengals drafting safety Taylor Mays in 2010, the Patriots drafting Tavon Wilson in 2012, the Falcons drafting cornerback Jalen Collins in 2015, the Colts drafting safety T.J. Green in 2016. So it happens, even higher in the draft than Williams was selected, and a lot of teams does it.
I am not saying Brandon Williams was not a reach, and personally I also felt it was much too early, but claiming that it was a crazy reach and that he would not get drafted otherwise is almost certainly wrong.