It's 100% because of the scandals. If it were a contract thing then there would be no old clips from live stages. I'm also pretty sure there's probably verbiage in the contracts that states they get use their image in what they did under contract even after they leave, otherwise they'd have to edit every MV.
Honestly it's ridiculous. It only draws more attention to it. Especially in the wide shots of the whole group. I completely forgot about Ilhoon's controversy because I don't really know a lot about BtoB, but that insantly reminded me.