Does Apple announce each model's end-of-life date (in terms of security maintenance) in advance?

As I understand it you generally have 5 years for hardware and software support with software requiring that you upgrade to major versions as they're released for continued updates. Perhaps someone can share a link or provide better details for software support/EOL info?

Here's their vintage/obsolete products info page: https://support.apple.com/en-us/HT201624

As an ordinary consumer using my phone, how would I know when it's going to become unmaintained and I'll need to buy a new phone (if I want to continue having security maintenance)?

This is one thing I think Linux distros could do better: not just advertising upgrades to the next release, but warning when the current release is (soon to be) no longer maintained.

They don’t announce it, but based on their current cycle, which has been going on for at least 5+ years, they drop support for an “A” chip every year. Currently the last chip to lose support was A6, so you should get about five years out of an A11.

They will force you to update your battery? Don't let their bad policies cloud your judgment....