Board Thread:Touken Ranbu Pocket/@comment-24.217.88.43-20160803024006/@comment-29158179-20160803041136

In my experience, if security reset does not enable a disabled Apple ID, sometimes Apple IDs get blocked because the use of the Apple ID outside of its designated region (in this case, it's Japan). It doesn't happen to everyone, but sometimes use of the ID (in-app purchases, downloading apps) flagged Apple to disable your ID.

I suggest contacting Apple support (and asking them to enable your ID) or making a new Apple ID to solve this. As for if it could happen again, yes, I'm afraid it could :(