It's certainly a risk to stand still but Leeds have the benefit of being the best team in the league by a distance, their major weakness is Meslier who has cost them a load of points this season. If they had Trafford in goal for example then they'd easily be 10 points clear of the playoffs, that seems the area they need to strengthen pretty urgently. Perhaps they're gambling that they go up and even better is available rather than pending money now for a smaller improvement but it is a risk, especially as those below have strengthened.
Sunderland look a good bet for a top 2 finish at 9/2 with Bet365, I'd be all over that if I weren't gubbed. Rigg, Neil, Bellingham and Le Fee is a pretty handy midfield.