rpvee said:

So is "Ren" the new "Sith"? I hope that wasn't to avoid using the term Sith, since the name did exist long before the prequels.

Hm...

Kylo Ren isn't his real name, but rather a title. He also isn’t a Sith. He’s a member of an organization known as “The Knights Of Ren" and he is allied with the First Order. Also, his lightsaber isn't a relic - it is something he put together himself.

While the term "Sith" did exist before the PT, I don't believe it was formally used in the OT. It seems like TFA is going back to the roots of the series.