A couple of links:I've never seen tire companies recommend such a thing. If you guys have a link handy, please do share it.
From Michelin: Mixing Tires | Using Different Tires | Michelin US
From Tire Rack: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52When replacing two new tires instead of four, be sure that your new tires are the same size and tire type as your current tires, and that your dealer always installs the new tires on the rear axle of your vehicle.
When tires are replaced in pairs...the new tires should always be installed on the rear axle and the partially worn tires moved to the front.