Earlier quoted context omitted.
WordPress uses phpass since 2.5.[1]. You can reset you password using an md5 generator, but that is due to the backwards compatibility in WordPress. In order to provide seamless upgrades to the new hashing mechanism, they hash is not updated until the user authenticates again. The password is confirmed against the old hash, and if it matches, the password is re-hashed using the new hash and saved over the old hash. S…
So http://codex.wordpress.org/Function_Reference/wp_hash_passwo... isn't in use anymore? Seems to indicate that the lowest common denominator is multiple runs of md5. I see that's pluggable, but I'm sure most WP sites don't bother installing an extra password hashing plugin, given a major part of WP's install base is one-click installs on shared hosting accounts by people that don't really understand what they're doi…
I believe that phpass portable hashes were used for their cross system compatibility, as prior to 5.3 not all crypto functions for PHP were available on all platforms. With 5.3 all crypto functions are now built in, so it should be possible to use the non-portable hashes of phpass everywhere, but I believe that WP still targets 5.2. The version of phpass shipped with WordPress has support for non-portable hashes, and it would be possible to make a plugin that enables this, but as you've stated, it isn't likely that many WP sites have a hashing plugin installed.