No, that isn't right.

Years before the first release of Clojure, Rich used to maintain a parallel build of Clojure for both platforms before concentrating on the JVM; but that is ancient history, and isn't relevant to ClojureCLR today.

ClojureCLR is a port maintained by David Miller, Rich doesn't work on it, so it isn't surprising that he hasn't made any comments about it.

Though it is true that the CLR implementation has much less adoption than the JVM or JS implementations.