Typing "alpha beta" into the search box shows a raft of questions asking about alpha/beta versions of Ubuntu, and the general answer is that they are off topic on AU because they change so quickly.
I have flagged a few as off-topic, but none of the options are really suitable. The closest is "off topic because it refers to an End-Of-Life version of Ubuntu" - which basically means that only current versions of Ubuntu are supported.
Should there be another option for "Prior to Start-Of-Life", or could the "End Of Life" tag be modified so it includes any unsupported version, whether because they are too old or because they are too young?
Or does it not really matter all that much?
(Might be coincidence, but it seems to me that EOL flags get actioned quicker than "Other - type your own answer" flags).