According to the queue, they were added because of their (lack of) length and content. When the system detects this, Community ♦ automatically raises a VLQ auto-flag that puts the answer in the queue. However, no flags were raised today or the moment they were posted.
Since they were never auto-flagged originally, is this a bug, or is this part of the system change that now puts Not-An-Answer flags into the Low Quality queue? If the auto-flagging system was around three years ago, then surely it would've caught them already.