Hello, it seems that you’re not the only one experiencing this issue.
Actually if you gave your iOS the permission to “auto-update” then there’s a good chance that your client has already updated.
However that seems to be not the issue, if that is the the case, because I have as well updated it manually, yet it still says that it requires to be updated and restarted.
Like the time when they were giving out snip snap and my iPad, for 7 months, could not access hearthstone, until the event timed out, and I reinstalled the game entirely, but it was too late and I had to craft it, it is so unfortunate that blizzards support for it own games seems to be degrading, and it doesn’t care for it paying users and fans anymore.