Google announced multi-user support for Google Home earlier today, but it's only launching in the US right now. This is finally a chance for Google to rectify things and add all those features Home was lacking at launch, and indeed Google has included a few new features. We're still missing some big ones, though. You still cannot create a reminder or add events to your calendar.
After going through the setup process for multi-user, Google Home has access to some of your personal account information. That allows you to ask questions about what's on your calendar, view photos tied to your Google Photos account, and so on. However, writing data to your account appears to be a sticking point. If you try to create a reminder or a calendar appointment, Home tells you it can't do that yet, just like it did before.
Hopefully the addition of multi-user support will let Google add these very basic features soon. Seriously, adding something to your calendar has to be one of the most common tasks for a human assistant. It's certainly not impossible to do this stuff, either. Assistant on the phone can create reminders and events just fine.