This is sort of baseless for more than one reason. Randall was a safety in college, and in his draft class he was regarded by most as THE best safety in the 2015 draft. His ability to tackle in space, as he displayed countless times during the 2015 season when he was not injured, was really good. If you'll recall the Carolina game from 2015, he brought down Cam on two seperate occasions on 3rd down in the open field, and many more times throughout the year.
Secondly, playing "slot" is not a demotion in today's NFL. A lot of teams top CBs play the slot in the nickel/dime/big dime/quarter sub-packages. IMO, Randall is in line to realistically be a top 2 corner for GB, and in sub-packages, he'll slide inside to the slot, much like Woodson did from 2010-2013 with Shields coming in and playing the boundary.
Finally, I think Packers fans are giving Gunter way too hard of a time for his play down the stretch last year. He had to play debatably the hardest trio of receivers in the NFL in consecutive weeks, and he held his own. It is so weird to me how people all of a sudden held Gunter to such a high standard, as if he was a 1st round pick, or even a drafted player at all... He was undrafted, presumably for a reason. The guys he was asked to match up with in Odell Beckham or Julio Jones are probably in the top 30 athletes on the whole planet.
For where he came from to this point in his NFL career & his path there, Gunter has done a wonderful job and worked very hard, and he doesn't get enough credit for that. Randall included. After his 2015 season, he looked like a rising star at CB. He played really well in 2015 & this year I do believe injuries played a huge role in his drop off.
I think it would be good practice for fans to try and empathize with the players a little more instead of being overly critical. I myself am only 23, and I can't imagine the pressure some of these young players my age are faced with.