They typically only give extra sub time if the maintenance is like 48 hours or they have lots of maintenances within a few day period, which has almost never happened (but my understanding is it will happen prior to Dawntrail release).

The DDoS just disconnects or lags you for a few minutes, it doesn't affect all data centers equally and it's probably not even targeted at SE directly (when I did a trace, the issues seemed to be the usual suspects like NTT while SE's servers had a perfect connection).