The bulge over the rear fenders (circled in green) might also suggest that this car is using the new FR platform.
It is definitely very similar to the MX30, which imo looks great and now looking at your comparison, even the front turning signal is similar with the one in MX30. Great comparison pics btw! Overall the design even though its an early spy shot I believe its great.
This makes me wonder if the CX-50 is going to sit above the CX-5. It looks larger, more aggressive (tail pipes) and the back looks a little like a Cayenne.
Not really sure you can drawn a comparison between the two. One is front driver, smaller and one is going to be rear-driven and bigger. Price wise it is going to be more expensive for sure therefore it will sit above (way) of the CX5.
As it was rumoured I believe they will keep selling both, at least for a couple of years because it is they're best selling vehicle and I am not sure how many people will want to go spend another 10-15K on a new Mazda.