I had blue screens happening but they weren't related to Fallout 4. I had incompatible RAM that was not supported for my motherboard and caused instability while mainly playing games. The only issue I had with Fallout 4 was the full screen black screen, the first time I ever tried Fallout 4 was on Windows 10 and had no issues from day one, I reverted back to Windows 7 because I thought my SSD was the cause and reinstalled Windows 7 on my HDD.

As for forcing an upgrade, I doubt they would deliberately hinder previous OS' especially when Windows 7 falls under the minimum requirement to run the game, that would be false advertising.. It could very well be lazy coding, it seems on these forums that black screen issues are related to Windows 7.