99s day one isn't hurting the game from what I can tell. I think people get too caught up on overall ratings. A lot of cards play better (or worse) than their rating.
However, the "re-grind 99" is hurting. People are having to do things over because progress isn't saving or is lost and rewards aren't being given. People having to re-do stuff they've already done in their limited time will be what undermines the game this year.