Yeah I remember the great DS Rio schism happened when Rose was rumoured to have broken up with her bf and LadyLav reported seeing him with her at Gio's show and was dragged for filth. Them splitting up, plus Gio not managing or wanting to have a public, stable relationship with anyone, gave the shippers hope, as you can project anything onto silence ('oh they're seeing each other in private'). If Gio had come out with Jowita at that point it would have put a big spoke in the Rio wheels.
With Ellie and V, now that she's public with Bobby, you have to be absolutely deluded to do that ('Bobby's a decoy/it's a PR stunt') so it's probably come at a good time to head off the vast majority of the shippers (who I think are not hardcore, just 'aw they're so cute together' types). Like one of my besties over Xmas asked me if she thought E+ V were an item and was hoping they were (I obviously pretended this was not a topic I had a Masters by Research in), but I can guarantee she's probably not thought about them since.