I assume, under the agreement with Cathay, that we will automatically assign the RF SID to anybody (777 or -8 ) who calls up for clearance as "CPA086". While an extremely diligent and not so busy CDC might look across to the cargo apron and see that it's actually a Polar aircraft and query whether RF is suitable, there's no requirement.
That's why I was querying if Cathay has made their wetlease operators aware of this agreement.
As you say, the crew does sound a little wrongfooted on receiving the 1E clearance.