OK the proximate cause is because None is passed here:

Need to determine it that is for a reason or just an accident.

passing models instead of None solves the immediate issue here. @mattpap this was last changed in #9198 is there any reason not to pass models here?

Edit: noting there are specific tests to check that all 4 bundles are included, but definitely not clear why that should be necessary.

This will require more thought, the current autoload script is not smart enough to load additional bundles in case a second autoload needs more/differet bundles than a first autoload on a page. This does not affect the gallery pages that have only a single embed, but does affect other pages that have many embeds.