What happened to updating the old-style base splash arts?

So a few months ago Riot was updating old, obsolete looking base splash arts on a pretty regular basis (just as some examples ), but lately it seems that they've stopped doing that. Champs like , , , ,, , etc., still have splash arts in the old style that need updating, but they haven't released any new ones for a while. Has the updating process been finished? Are there no more plans to update these older champs' splashes?