Who really knows the dynamics of the OEM supply chains?  I recall a former employer signed a development deal with Ford Auto 5 years prior to putting the first yard of fabric in the Taurus interior.  Since I doubt that any screen supplier gets overly excited with B&O volumes, it would logically follow that meeting B&O's demands comes with a price tag or contract that other makers would not accept.  I also guess it's not easy for B&O to adapt to the line changes the OEM makes in order to do 2-3 model variants in a year, and even harder to change suppliers quickly (but that is truly a guess).    

This would seem to add up to the need for B&O to make decisions very thoughtfully: not something the consumer electronics industry tends to respect.  Even Pioneer admitted to losing around $1500 per piece (and that's what they admitted to) during its heyday with the "legendary" Kuro, before they left screen production.  Now you can buy Pioneer Elite on Amazon.com.  

As far as cost-cutting on screens to make a profit goes?  I really doubt screen price was/is that big a driver.  Outside of scarcity, the solution for luxury electronics would then be based solely on the capacity of Chinese labor and the resilience of Chinese rivers.  History addresses the concept many times.  Only the names have changed.