> I imagine Mozilla's thinking there was that they should position the feature so that people who already use Pocket will realize that Firefox isn't adding a separate reading list (like the Safari one nobody uses), but rather that you can just sign into your existing Pocket account in Firefox, and see your existing Pocket reading-list.

That was pretty much how it was viewed at the time (I worked at Mozilla during the Pocket acquisition). It was seen as, "we were going to build our own reading list, but let's just buy this instead and integrate it as /the/ reading list for Firefox."

I agree that the external perception was different, and remains so to this day.