It's clearly just as misguided to report a mortality rate based on unresolved (death or recovery) confirmed diagnosis. There's simply no way it's 2% or 4% as reported. The argument over what the mortality rate is, is probably as good as bike shedding at this point. Inevitably I will be wrong, you will be wrong, and the experts will be wrong until it's over, or measured over some temporal range.
It's fine to report it. It's maybe not a great idea to publish it to an audience who don't understand what they're looking at.
Actually, I do believe you and I are in the clear - I don't think either of us has stated an estimate of what the mortality rate is. Given that the "experts" being cited in the media are offering such widely different estimates, then presented by the media as "facts", it's a horrific situation.
As for measuring enough cohorts infected - or at least diagnosed - at about the same time, then monitoring their progress over a reasonable time frame (maybe a couple of months), the first and best chance of getting that data is from Wuhan. So far, I'm not confident that they're going to deliver.