Scootaloo has canonical parents now, and Dizzy Twister isn't one of them.

Of course, that doesn't mean this group has to die. There's still plenty of avenues to explore. Dizzy could become a step parent or foster parent to Scootaloo, there's always adoption. And there's plenty of AUs that can still use her.

No indeed.

The many headcanons of orphan Scootaloo have been with us for nine years.

Throwing all that out after a canon revelation in the final season would be a very bad thing.