I'm not sure what CX's technical protocol is, but from experience that's the ISM's gametime call. Some ISMs try to keep service very quiet on late-night flights. Count me as someone who appreciates it when they do. I CX fly ex-US every ~6 weeks, mainly on late night flights and I prefer the minimalist service in J as I'm usually trying to sleep. I will have already eaten dinner in SFO, LAX or JFK, and usually pass on food unless I'm in F.

Fyi, a full service in J on a normal flight can go up to 2.5 hours after takeoff, and is tough to complete before 90 minutes have elapsed after takeoff. And a fast service full service is a loud service, plus the cabin lights must be kept on during the service. It's a matter of preferences but I suspect I'm not the only one who prefer the lights off and quiet as fast as possible.

On CX, the crew expect you to use the flight attendant call light for servicing needs. It was an adjustment that took some getting used to when I moved from the US - where use of the call light seems to be shunned - to HK, where you are expected to use it proactively for your food and drink needs. It's not considered rude or impolite to use the call light, rather on a flight like yours the crew is probably fully expecting pax who want a little more to bang away at it.

Now...if they would only stop the droning announcements in multiple languages during turbulence...but that's another issue.