Before, WRC2 was for registered teams and their drivers, WRC3 was for rest of drivers. But now, WRC3 is "beginner class" (there are some rules about who can drive), and WRC2 is now for registered teams (both factory and private) and also for individual private drivers.

So they took concept of last year's WRC2 and they expanded it with "experienced" drivers with no team.

Hope I managed to explain it to you.