Yeah, pretty much. The "thing" about Mindmaster is that you don't lose from not being able to draw because you don't start with libraries.Isn't that exactly the same as if the player with The Mending of Dominaria had an empty library anyway? You'd still get a Reanimate out of Chapter I and Chapter II, assuming that you had a way to avoid losing from trying to draw from an empty library.
Not sure what you guys do about Chapter III though, if the idea is that you don't ever have libraries at all. Has this ever come up before? What happens with Time Ebb?
You can have libraries if any cards put cards in the library, like Chapter 3. You just don't start out with libraries. And then once you do have a library, any cards dealing with it no longer become useless (well, depending on the effect of course).