http://www.cheatsheet.com/entertainment/star-trek-discovery-cast-reveals-why-the-klingons-look-so-different.html

I thought the Klingons were looking a bit different in the last teaser. Not sure I buy into this article's reasoning. First, the Klingons don't change appearance in every show nor are they constantly changing. They changed in The Motion Picture from how they looked in the original series and then never changed again after that. Yes, each Klingon had a distinctive ridge pattern and we've seen Klingons with darker and lighter skin. We have seen bald ones, too. But to say that now they all have to be bald because they have sensory-ridges on the back of their heads or they have jet black skin and to say that this is all done to honor what came before doesn't seem quite right.

Once again I feel the need to point out that if you're going to do a prequel, especially one set only a few years before the prior series, you should constrain yourself to things that will make sense within the confines of that original story. It looks like in this case they wanted a brand new alien race that are not like the Klingons and they are just using the Klingon name because it's what's known.

And to say that they look different than the ones in the current feature film series to signal to the audience that the show is taking place in a different universe? First of all, shouldn't they try to coordinate efforts with the films, shouldn't they being trying to draft off the movies' success like Agents of SHIELD does with the MCU? Second, if the Klingon race has been around for thousands of years then why would a timeline change that only affected 30 years of history so far suddenly change their genetic makeup? I mean c'mon. Come up with a better excuse.

"There is a whole reasoning behind it that is adhering to what has always been true in Klingon canon…"