So despite all the yelling and screaming, GD still has 77% of the capacity it had before the engine was changed. Especially when you consider that maybe half the accounts lost were coaches that had teams in multiple worlds (and even additional accounts in the same world), the amount of retention despite the decries of an inferior product is rather amazing. That is far better than what was expected by us users and I think what GD could have hoped for. It would be interesting to know how many new users (never played in the old engine) there are now but, of course, that isn't readily available data.
Obviously, a successful update to the game would have increased the number of coaches. The game looks like it will survive but until they fix some things, its obvious that it's not going to thrive. Thanks for the update, atcchris and dansonball.