Welcome to the Q&A Forum

I agree with you that I would probably leave them up. Redirecting those posts would likely sacrifice your ranking positions as you mentioned. Your best bet might just be to create a new Google Analytics that removes the entire blog or at least those two posts. For your core reporting, you could just use that segment. That should allow you get the traffic but report your core KPIs on more relevant pages.

Isn't the key factor that "The decision has been made that e_ach product will have their own site moving forward_. "? It seems like the Suits have spoken on this and that your job is to get the products onto their own sites in the best way possible.  But if you rel-canonical Page A-->Page B,  people will still be able to visit both URLs and that's not what they're directing. To me, it sounds like 301's across the board and then move on, no?