To improve security, we will soon start forcing password resets for any account that uses a weak password on the next login. If you have a weak password or a defunct email, please update it now to prevent future disruption.
I doubt it. Apple is popular, but not that popular. Especially enough to bring down a platform ran by Microsoft.
I'm guessing it probably has something to do with upping the security. They've seeing a huge surge is account hacks, malicious bots, and CP being uploaded to servers and reported en masse. They won't admit it, and probably never will. Just an assumption, though.