As I've stated before , leavers in solo shuffle ranked are now live

^
What the blue quote is saying, is that the rating won or lost, both MMR and rating (although he’s just saying MMR because MMR determines the rating won or lost), is determined based on the MMR relative to each other each round, and then also affected by your own CR relative to the MMRs each round (although since the blue post didn’t mention rating at all, he therefore skipped this part).

So your suggestion in the first quote, wouldn’t work like that.