Why only selected paragon character models are released?

I was shuffling through the paragon’s character models available on Marketplace after they were released by EPIC, however I saw that not all character models are released , some of them like Lt.Belica ,sparrow etc are not present.

I wonder what was the selection criteria for the models that were released and if there’s any possibility to release the remaining ones in the future.

We will have a future release that will include more characters!