@Background Pony #BDE6
I don’t think Spike’s absence from the episode was accidental. The episode hinges on the fact that Maud is so unlike any other pony, to the point where the other ponies can’t relate to her.
Spike is a similar odd-man-out, being a dragon and all. He would appreciate Maud’s oddity, which would take away from the dramatic tension caused by the other ponies’ failing to do so.
Still, if Maud ever returns in a future episode, I hope she and Spike get some screentime together. They would make a cute couple.