As for Composer 1.x, it is now more or less EOL. It will also receive critical fixes if anything comes up but the goal for everyone should be to migrate to 2.x as soon as possible.
Reduced v1 metadata API update rate starting in May 2021
The update rate for new versions will be reduced from every-minute currently to once every 15 minutes. This means new releases will take a few minutes longer to be available for installation with Composer 1.x.