The Tellarites, regardless of tie in material or fan wishes, have minimal development, probably because there isn't a lot there to begin with.
I mean, that's not a reason why they couldn't be expanded if somebody set down to do it.
Look at the Andorians, they had hardly received any development in either for most of Star Trek, yet what Enterprise did with the Andrian and Shran is one of the things about ENT that even people who aren't fans of the overall show (like me) often like.
They played an important part in DISC's third season.
And now on SNW we even have an Andorian main character.
The same could be done with the Tellarites if a show runner or writer decides so.