Splash Art Updates?

Obviously as more champs come out or are reworked, the older splash arts become... dated, and while several have been updated, many haven't. I'm sure Rito has a team for it, and I understand it isn't a priority as it doesn't change anything other than looking pretty, but there are some that desperately need attention. Like every single skin for in particular. They still depict pre-rework Sion! Is there a splash update schedule?