You are technically correct that there is not a formal end-of-life, but rather a point at which you will stop being able to update because there’s no longer a m

You are technically correct that there is not a formal end-of-life, but rather a point at which you will stop being able to update because there’s no longer a maintainer working on backporting patches for that device. At the end of the day, lineageos is best effort from volunteers, and you should weigh that fact when you decide what you want to use day to day.