I see an awful lot of questions on EOL releases, and I think that this site should have some automatic features to help combat it, as it is really quite a major thing with the quantity of them.
So I would propose the following methods as examples of automated methods there to prevent the posting of EOL questions, and educate users that it's time to upgrade:
If someone tags their question with a tag associated with an EOL version (such as 13.10 or 14.10), then when they attempt to post their question a popup will come up (probably as large as the one that gives you options when you want to VTC or flag a question), which will remind them that if their question is about any of the EOL releases then it is off-topic and will be closed and that they should upgrade before they ask. And then give helpful links etc.
To display a notice beside the question if it contains the release version, or codename of an EOL release, which reminds the user that EOL releases are off-topic, and that support will not be provided for them.
If the title contains a codename or release version of an EOL release, to show that little red popup next to the title also reminding the user that it contains a keyword of an EOL release, and that those questions will be closed.
Have some sort of queue, or include in another already existing queue, questions which are likely to be asking about EOLs because of keywords contained within them. Obviously the questions would be posted, and not be waiting for approval, instead the queue would just be a queue of questions which the system detected as questions which may be off-topic and need closing.
Sending an email, or other notification, to all users when a release goes EOL, and that support has ended on AskUbuntu for that release, and that users are advised to upgrade.
These are just some of many examples of automated techniques which could be used to inform and deter. Is this something that could be implemented in the future?