Doug Jones, in an interview for IGN:
At first I wasn't sure what to make of them introducing a member of a new species amongst the main cast. Initially my response was that of skepticism because this new series is a prequel and that's exactly what they did with previous show Star Trek: Enterprise (another prequel) when they introduced John Billingsley's Denobulan character 'Phlox'.
But my skepticism started to fade when I thought about how Star Trek has always used the most unique "alien" characters in each series (namely Spock, Data, Odo, The Doctor, and Phlox) to best explore exactly what it means to be human. It's a formula that's been used in every series so far and it's one that's always worked very well, so I can absolutely see the sense in them wanting to continue that tradition. I do like what Doug Jones says about having the freedom to explore and develop his character fully rather than having to be slightly restricted in order to slot in to the previously-established traits of an already existing race.
I wouldn't be surprised if another member of Lt. Saru's species makes a cameo as a background extra in the next Star Trek movie, to help tie it all in. Denobulans started popping up all over the place (even in video games) following Phlox's debut.
Thankfully Doug Jones is a very talented actor and it will be interesting to see what he and the writers come up with for Lt. Saru. Also of note; interesting pronunciation - not what I had initially guessed.
Filming on Star Trek: Discovery begins later this month and the show makes its debut in May.