The evergreen no date thing is fine with me - provided the content itself is actually evergreen. That's the bit people seem to forget. Not dating content doesn't magically make it last forever. If the information is unlikely to expire then I don't need a date. If there is a chance that the information will go out of date, especially if the dated information will not be useful to the reader, then it should be dated.
I have no idea why this is downvoted at all, let alone downvoted so heavily. It's correct. The content will be out of date in five years, so it's not evergreen and should be dated.
The evergreen no date thing is fine with me - provided the content itself is actually evergreen. That's the bit people seem to forget. Not dating content doesn't magically make it last forever. If the information is unlikely to expire then I don't need a date. If there is a chance that the information will go out of date, especially if the dated information will not be useful to the reader, then it should be dated.