It will surely result in spam for 3.0.2. But it does not really matter, does it? With every new client there have been preliminary test patches, and even though they where published unsupported, people demanded support.
Maybe doing this in the public and demonstrating the work behind a client update may change some peoples attitude to be less annoying about upgrades for the future.
Well, maybe that will not happen. But we have not tried that yet, and probably doing this in the open might help. And if it does not change a thing, we will still end up with the same situation. If we create client updates in private, and then suddenly switch, we still end up having update spam in the meantime.
I'd just hope for some positive change, when doing upgrades in the public. If it does not work, there is not much lost. I would not enforce the public upgrade, I just think it might make a difference in the peoples attitude and give us the chance of some real testing. As expressed in some other topics, there are people out there interested in the upgrade process, and some even might be willing to help or at least provide valuable feedback.