If I'm not mistaken, didn't Jon say how much he disliked playing OLB when he went back there a few years back? That's hard to just ignore and think it would be no problem. Plus, the guy does have coverage problems as much of a beast he is. I feel like everyone is trying to ignore when he went back to the outside under Fox and played actually quite underwhelming.
Its easy to just say he can slide on over but this may be the casualty that could be hard to accept and happens midst all of this speculation if the numbers mentioned are in fact true.
I don't think he actually said he dislikes playing OLB, just that he prefers MLB. Splitting hairs, and most likely his actual feelings are more on the "dislikes OLB" side, though.
However, Beason is quite a good coverage LB, one of the best in the league in my opinion. He's very quick, changes speed very well, and has even covered WRs well in the past. Of course, his return to that ability depends on recovery from his injuries. But using the past as an indicator, coverage is not his weak spot. The only weakness I've seen was his tackling this year. Hopefully that was just a result of trying to be too cautious of his injury.