its actually nothing new,
Wizards already did three free mini PDF settings, For Zendikar, Innistrad, and Kaladesh
And the reception for all 3 been positive. So Ravnica gets a actual serious Hardbound book with a Price tag on it. I hope Dominaria is next.
Shoot I hope they go the other way as well and we get MtG cards based on D&D settings, Greyhawk, Forgotten Realms, and Dragon Lance.