Why does it need to be point to point traffic though? Passengers were always able to interline before alliances and they are still able to do so. There is nothing to stop EI pax from going on with EK to Oz for example.
EK have said themselves that there is a huge amount of Irish pax on their services ex UK. That alone is what has had them looking at DUB for a couple of years now. These pax are hardly connecting onwards again via Dubai after connecting already in the UK when they could have made a single connection at Heathrow.
South Africa may not be the great bet it was made out to be initially. There are rumours traffic was soft on the AV8 services. ex DUB. (Open to correction on this point: don't know for sure)