Lounge Locations | Europe | United Kingdom | London Heathrow Airport | International Lounge
They appear to have changed the access rules overnight in conjunction with the lounge opening.
No access by dint of oneworld emerald/sapphire status when travelling on a flight marketed or operated by EK, but if traveling so in F or J then yes with the updated rules.
I'd expect many eligible emerald PAX to continue to use the CX F lounge (or AA) - à la carte dining with a reasonable variety of choice. Also, gin doesn't do it for everyone while Champagne I would suggest is more popular; with also (Noting that Champagne is not listed as an available beverage; in practice I suspect something discretely different).
I suspect Qantas won't be advertising to QF PAX any other option other than this lounge. A bit like the availability of the AA T3 arrivals lounge for QF inbound First and Business passengers - that is no longer advertised on the Qantas.web site as an option, even though it continues to be the case.