Not exactly correct. Proof of Stake had many inventors. At the time Peercoin was announced, there were already discussions in this forum about other Proof of Stake concepts. NXT, for example, was modeled with an earlier PoS implementation in mind. Examples for early PoS discussions:

Proof of stake instead of proof of work (July 2011)
Proof of stake (March 2012)

Peercoin was released in August 2012 (see here). I don't want to dispute its historic significance, but it wasn't the only PoS protocol being discussed at that time.

It's not pure DPoS, because there is no static number of "delegates", like, for example, in Bitshares or Lisk. In Ouroboros, validators are elected for shorter time periods and the number can be higher or lower depending on participation.