However, on the off chance that these hackers have gotten a hold of an administrator's passcode and downloaded these data, it would probably be a good idea to change your AppleID passcode before the April 7 deadline to protect your data. Apple will most likely be changing its access protocols and passcodes as well to assure no further breeches if any have occurred in the past.
Again, I doubt such a download of such a large amount of data has occurred as it would have raised large red flags for system admins at Apple and been stopped in its tracks, but it is better to be safe than sorry.