Depends what timelines and what types of users were talking about, in my opinion. Users migrating who have contributed good content and/or moderation should have the patience to get through most of the growing pains. Casual users who show up just to browse and maybe up or downvote a few things don’t add a lot of value up front anyway, so the attrition of those users won’t matter too much in the long run. Those types of users will likely be back in the future once the kinks get worked out, or will be replaced by users of the same type. Patience is the game.