It's tough, they have needs at both CB and WR.
I've said this a whole bunch, I think whatever of those two positions they don't pick at 7, they pick the other at 71.
I'd personally prefer to go WR first, then DB at 71.
Keep this in mind about Tate, and I've mentioned this before also: He wasn't the #1 WR on his own team. Jeramiah Smith was the #1 WR at Ohio State. He's not draft eligible. It's VERY possible that even though Tate is the best WR in this class, Peters and company don't thing he's really the best prospect for that position and doesn't grade out as a WR who could replace Terry as a #1. If that's the case, and they think another player could be the "star" at their position, this is the very concept of Best Player Available.
Now, I have no idea who they have rated higher. Keim indicates that it's Delane. The only way we know that for sure is if Tate and Delane are both available and they pick Delane. Which might happen. Though, I'm not sure, I actually think there's a reasonable chance Tate is gone before 7. Otherwise, we won't know.
I wouldn't be mad at picking Delane. But in that case, I think they're going to have to suck it up and overpay for Jennings, and probably add Aiyuk when he's available, and draft a guy at 71 just to get to the season with something resembling a reasonable WR room.
I will also say, it must be pretty frustrating for Peters this year that he identified a need at WR, threw really good money at the top 2 WR prospects, landed neither, and then might feel that the WR they can pick in the draft isn't worth the pick they have.
There's also the possibility this is all a smokescreen, and Tate is there, and they pick him.