Two separate issues being discussed...
1. Here's where I disagree with the OP. When waiting for a CPU, I think United has every right to try to sell as many of those seats as they can. I want them to. I want them to continue to be a profitable company and if they can get some revenue, then great.
2. But as others have said, if someone has a supported upgrade waitlisted (RPU, GPU, Cash, Miles, Instant 1K, etc.) then United should NOT be selling those upgrades.
(Edit: I mean the OP of the thread I responded to about CPU's - not the thread this was merged into.)