Whittaker taking his sweet time is smart. If Izzy moves up he's likely champ again. Why get wrecked a second time if you can just wait until the guy moves up, and then be the immediate challenger for the belt if he vacates.
That goes out the window if Izzy wants to defend both belts I suppose, but I'm thinking if he beats Jan then everybody is gonna be calling for the Jones matchup immediately. Not to mention there aren't any fresh exciting matchups at 185 regardless. His days at middleweight are probably done if he gets that 205 belt.