I'm thinking that the figure your quoted was probably something said before launch. The launch was originally planned to be simultaneous but ended up being Google first and Apple about a week later. Also the thing I've learned is a global launch doesn't mean available everywhere straightaway it seems a couple of weeks are needed to propagate at a global level.
One thing I do know though is there is more to be added to Gravity, I wouldn't be surprised if the ION team hold back on that kind of information until Gravity has been updated to it's full potential.... i.e. more worlds, bosses, weapons, etc. When they do decide to share I would expect them to share the active user rate too as downloads is only one element you would use to measure success.

Actually the figures I quoted were from Huey on Saturday of last week, if I remember correctly, so when the game had already been released to the Play store. You're right about it not being available immediately on the iOS App Store, for whatever reason, though the gap was a lot less than a week between the releases (android on the Friday and iOS during Monday into Tuesday). Anyway, from what you've said it doesn't sound like whale status affords you any further information than can be deduced from review rates and the download estimations on the Play store.
I will admit that I'm somewhat baffled as to why there doesn't appear to be thousands of active users, as the fact that the community was apparently thousands strong was touted by the team as the reason they couldn't do a closed beta for Gravity (apparently the size of the community exceeded the amount of users you can invite to closed testing schemes for apps in the Play and iOS stores). Where have all those users gone?