Depending on the target and the severity of the vulnerability the vendor might consider fixing the vulnerability even if EOL.

If the target is an IOT device the vulnerability will likely be mass exploited to create a botnet.

The U.S. government recently ‘took control’ of a botnet run by Chinese government hackers made of 260,000 Internet of Things devices... (Source: https://techcrunch.com/2024/09/18/u-s-government-took-contro...)