It may be an indication on how unsuccessful previous releases were - I would think "holiday" ponies look less and less likely - they rushed out V Day Pinkie and then Easter Fluttershy but we saw nothing for Halloween or, most significantly, Christmas.
I would guess from the amount of x-stock which seems to show up of Easter Fluttershy [our large TK Maxx chain in the UK has loads of these] that these releases were not popular sellers and in turn this would probably make HB reluctant to try holiday releases again [at least for a while]
I agree. I think that since Valentines Pinkie Pie and Easter Fluttershy didn't seem to sell good they might have backed off the idea. I think they would have sold a whole lot better if they would have made new ponies for the holidays. Like they did for most of the G3 line. I bought all those holiday ponies but I have to admit, I did not buy last years G4 Pinkie Pie and Fluttershy versions. I didn't think they were different enough. Seemed like more duplicates to me.
I thought they were going to turn blind bag Lovestruck into a regular size pony for this year's Valentines pony. After all she does have a cutie mark just like Always and Forever. And then maybe turn one of the other blind bag ponies into the Easter pony. But you'd think they would be out by now or we would have at least heard of them. Maybe next year.