First of all, never underestimate the lack of consideration of the general public. If they're anticipating a patch on a particular date, even though they know it's only an estimate, there'll be hell to pay if it's not available. Secondly, they may not even be able to give a firm ETA as there might be some issues that will take some time to resolve. Or fixing one thing might break something else which could set back their ETA for weeks. Then people would really get irate. Diplomatically, it's best to not say anything at all.