Well - it looks like my 3rd BRU-DXB is still the old first but they've changed the 10th back to the new first.
I bought my ticket through an agency.
Of course it's a holiday weekend so I called the regular EK line and got a nice agent in Dubai who told me the agency would have to contact their sales support for authorization.
He said even the reservations supervisor would have to escalate it via email to their manager.
I asked him there was no manager on duty who had the authority to make a change on an Emirates issued ticket with just EK space from BRU to GVA and he said no way - that again - no one at reservations could do it.