Ultimately it's a demo until everything is reintroduced. There's no need to play these wip-updates, unless you really have time to spare and don't mind replaying stuff again later on.
From the changelog:
- Partially completed route for Miss Dewitt, with the rest due back in a future update.
They're gonna run into trouble if they keep having to play catch-up every patch like this
If I had to guess (I haven't played and don't know what's there), it's because of how much Eve and the 3 guys from the park are involved in that story. Given how outdated that content was, DC may figured it would make sense to change a few things and they need Eve's story, so the changes are workable and make sense.
So how much is still missing?
You'll need at least two more updates, so there's really no need to play before the end of the year. Right now it's just Jennie, Debbie and the teachers.