The Pennzoil Full Synthetic High Mileage looks to piggyback off the All Mileage (Synthetic blend) Quaker State in marketing it towards new cars as well as older, per it's PDS. Valvoline was the first to do so, as i remember.
I would say that it's not Dexos approved, but I just found the individual quarts listed on Walmart's websits and they do say that it's Dexos approved, as of yet they have nothing about it on their weebsite.
It's my guess that they're trying to attain some new shelf space. I highly doubt these are going to be big movers so paying for a license is probably not worth it. The people who are chasing down the licenses for dexos essentially would be general motors owners only cuz it's their spec it's not something that anybody else created. I would look more to the acea specifications and just find the proper oil and use it. To be fair, this would be a decent budget synthetic oil that you're not getting tied up in the being the consumer and paying for these labels. It appears lately that motor oil has taken on a higher than usual price increase and some people would soon just have a decent oil and not worry about all the fancy lettering. I'm willing to bet they're also trying to hit a price point and they too realize that the oils that they've had on the shelves while they might be a higher tier or certification if they can't get that oil to move it's going to sit on the shelf and oil that sits on the shelf doesn't sell an oil that doesn't sell gets kicked out or put on clearance to never return.
Toyota doesn't have any particular approvals and at this point Honda HTO-06 probably doesn't matter much like GM 4718m and 6094m, ILSAC GF-6A and Dexos 1G3 are likely more stringent.
Most consumers are not educated or smart enough to know the difference so marketing works to sell more. It's sad to see how population's getting dumbed down on purpose and the process is accelerating lately.