Oh, in case anyone was curious, this is what zpool upgrade returned, so
these features for some reason weren't enabled before.
clug at rooster:/home/clug> sudo zpool upgrade
This system supports ZFS pool feature flags.
All pools are formatted using feature flags.
Some supported features are not enabled on the following pools. Once a
feature is enabled the pool may become incompatible with software
that does not support the feature. See zpool-features(5) for details.
POOL FEATURE
---------------
media
spacemap_histogram
enabled_txg
hole_birth
extensible_dataset
embedded_data
bookmarks
--