Literally this. Even in older games journalism there was a difference between additional content and true expansions. We used to call developers out for labelling something as an expansion that didn't have enough additional content. This is pretty close to what full expansions used to cost ($20-25 is what I remember for something like Shadows of Amn), and the amount of additional content fits.
I think a lot of people are used to the incremental and constant content release for live services games that are generally free. More is not always better, though...and free is not always free lol.
sailsperson