The last few videos they've outright said it isn't prime, and they keep referring to Trek as a "period drama" for why they can't update visuals. This entire notion is absurd because "prime timeline"just means discovery won't contradict other prime stories, it's the events not the visuals. Nobody thinks TOS is our future, it's the 23rd century through the prism of 1966. DSC is the 23rd century through the prism of 2017. The trekyards guys got especially down on DSC in there video on the transporter room. They said "maybe one day we will get a primetimeline trek, but clearly this is disco-verse". Further they've repeatedly accused cbs of being dishonest with fans about it being primetimeline. It's visuals are reimagined, it's stories fit cannon (if they don't even I'll turn sour on the show but we won't know till we watch it.).I thought Trekyards were pretty objective in their analysis. Granted I didn't watch all their videos, so I might be wrong. And I have to agree it does not look or feel like prime universe for now, but that does not necessarily imply negative.
EDIT: on topic, it is good to have Frakes back. I was happy when I read the news.