Are you suggesting there is a seat blocking policy for higher elites, or there should be? If the former, can you direct us on here to it?

IIRC, PMUA, way back in the day, maybe even before they allowed people to pay, and when *G, and folks on Y fares also got E+ access at no charge, used to have such a policy. There is a very occasional report of some sort of anecdotal evidence of seat blocking, but nothing has ever been confirmed and likely is a coincidence. LH used to also supposedly block Y seats for *G, though can’t remember.

On the the other hand, I’d guess it’s completely against policy for FAs to move folks without charge from E- to E+, unless there are operational reasons for it. I.e, E- full and assigned E- seat is inop, overfull E-, weight and balance, etc. maybe that’s what happened, or maybe theees a less sinister reason. Perhaps these seats were originally assigned to folks who no-showed , and GA let the FA know that there were elites in the back who requested to move up if they became available. Or NRSA. Weight and Balance would unlikely be needed on a wide body, but it’s probably possible.

Also, while OP may be miffed at losing a row to themselves, that’s certainly not an entitlement, either. Disappointing, maybe. My attitude these days is to assume that every seat on every plane these days will be occupied. So while I will try to select a seat where the empty next to me is most likely to be the last to be selected, I always figure it’s a longshot, and expect it will be full by the time the door closes.