It's actually interesting, once a year, there is a topic asking about either errataing or banning slowking. I don't think it'll be changed. PUI's focus is on modified, they wouldn't go through the trouble of placing erratum on a card that has been out for so long, not when so many other cards would also need to be changed as well. For example, the non holo dark vileplume, or Unown D, M and N.