In reply to Richard Rottman.

All Wordpress needs to do is this, with enough lead time AND to articulate an ongoing policy so hosts and devs know the roadmap. Me, I'd suggest this:

Minimum: The lowest version supported by PHP. Currently, this is 5.6.
Recommended: The most recent official PHP release.

Remember, PHP end of life dates are publicly available at http://php.net/supported-versions.php. It's not like they sneak up on people unannounced.