Had a perfectly excellent pre-work play at this today. Only after my hour was up did I realize that I didn't get in a single fight. It wasn't all cutscenes either, I was actively playing the game and doing stuff, just not combat stuff. That's really cool.
This isn't true in the body of the books. Yes, SPEW itself gets mostly dropped after book 5, since there's that whole war thing going on, but Hermione does consistently dedicate time to house elf rights through that time. This includes directly advocating for freeing Kreacher, and generally being concerned with his welfare through book 7.
This is just not an accurate description of the text. Dumbledore's Army does not take on the Ministry and win, they get broken up after a couple months. By the end of Book 5, only Neville and Luna show up when Harry calls. Nor do they defeat the Death Eaters, they are pretty clearly losing the Battle of Hogwarts, and that's with substantial assistance from a lot of other people.Of course I don't expect a teenage girl to overthrow an institution that has existed for centuries even if that's what Dumbledore's army actually did in books 6 and 7, taking on both Voldemort, the Death Eaters, and the ministry of magic and winning.
Overall the text (not whatever Rowling has said since, just the text of the books) is very consistent that, while occasionally a bit questionable in how she expresses it, Hermione is genuinely and consistently concerned about house elf welfare and liberation. The text is also consistent in showing that refusing to take house elves seriously as beings worthy of respect is a moral and practical mistake by wizards, and that Hermione's concerns are fundamentally correct.