https://www.patriots.com/news/belichick-wraps-up-2020-nfl-draft
So does not taking WRs/RBs an implied FU to Brady that BB thought he did have the right weapons? And did taking an entirely new OL an admission that the protection was as bad as we thought?
I'll start with OL. In his drafts, Belichick has taken 1, 2, 0 (only 6 picks), 0, 0, 2, 2, 3, 0, 4, 2, 2, 0, 0, 3 (Stork, Fleming, and Halapio), 2 (Tre Jackson and Mason), 2 (Thuney & Karras), 2 (of 4 picks), 1 (Wynn), 2, and 3. Basically, in most years, he picks up at least a couple. In many cases, with the exception of guys like Light, Mankins, Solder, Thuney and Wynn, it's been in the mid-to-late rounds. He picked two in the middle rounds last year that spent the entire season on IR; no real way to know if either will ever contribute, so it made sense for Belichick to hedge his bets with two 6th rounders and one 7th. I wouldn't call that "taking an entirely new OL".
As for the RB's, the team already has White, Burkhead, Michel, and Damien Harris on the roster (as well as Bolden, but he's mainly ST). It was probably their least important position to fill in this particular draft.
As for WR: it's probably an admission that neither Harry nor Sanu were completely healthy. Not taking a WR may have been the riskiest move he took with this draft, but there's also no point in taking one that will not fit on the team either.