Why weren't there Scootaloo and Sweetie Belle blind bags for so long?

[Dec Browne 20]

Blind bag ponies have always been the brushables' smaller-but-cooler cousins and were even the first MLP toyline to include male ponies. But until the Nightmare Night Friendship is Magic Collection in 2016, the only Cutie Mark Crusader we had was Apple Bloom (not counting Babs Seed). Scoots and Sweetie weren't even in the Class Of Cutie Marks Set, Ponyville Newsmaker Set or Pony Lessons Set, taking a back seat to side foals Diamond Tiara, Silver Spoon, Twist, Snips and Snails. Something very fishy is going on here that we don't know about. Hmm...

[Octavia Heartstrings 28,406]

Because releasing blind bags of Sweets and Scoots immediately would make too much sense. 

[ToastedScone 379]

They have very different body types to the other blind bag ponies; smaller and more petite, and thus an expense, as a new mould would have had to have been made. Hasbro was probably waiting for them to become popular enough to make the expense back before they wasted funds on a new mould. That's my two cents on it, at least!