You are talking about PoW algorithm, whereas our use of DAG, specifically DERO-DAG, is for network consensus, which is first ever to be used with CryptoNote, and is PoW based, so Dero will be using a mineable DAG
PoW algorithm is not mentioned in this update
The wording in the update, "DERO-DAG is mineable, POW based, fully linear with same level of security as blockchain," sure seems to imply it is talking about a change in the PoW algo. I may be drawing an incorrect conclusion here, but it certainly is a reasonable one.