What they are really saying is they don't want third party contributions. They don't have anyone triaging Issues or PRs so don't send them.

They will occasionally make changes if it aligns with a new product effort driven from within the org.

Saying they're dropping support is a stretch esp as very few people actually pay for their Support package anyway..... (Yes they do offer it as a paid option to Enterprise customers)

This is on the checkout action too, by the way. You know, the very first thing people put in their CI pipeline.