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I suspect RV manufactures don't install Blu Ray players because of cost, availability and demand. A quick peek at iRV and Furrions' websites didn't show these two RV stereo suppliers even offer Blu Ray as an option on their RV units. This site also reports the declining demand in physical movie media as more people shift to digital media:
https://arstechnica.com/gadgets/2019...a-report-says/ It also states the traditional DVD accounted for nearly 58% of physical (disc) sales in 2018 while Blu Ray accounted for just 5.3%. With more people turning to streaming, I think the end of the DVD and Blu Ray will be in the near future.