No rush really. Just trying to clean SU up from all the migrated out and off-topic questions that are just hanging around like a bad smell.
Been meaning to do it for a while. Timing wasn't considered beyond how long a question has been festering, so those with at least a couple of months were the first to burn.
They can later be undeleted and migrated whenever that option comes around. And seeing as there is no guarantee that any SE site currently will live, that's up in the air.
They can also be accessed if you download the Creative Commons Data Dump for SU. If a bulk of deletion is happening in one particular month, you should be able to download the month before that to see and reuse, with attribution, the data and posts from it.
Which may be handy if you want to cherry-pick through questions and answers to repost on the new Stack Exchange sites.