Coincidence? Win 10 saying bit locker security has changed and won't boot

[picnic]

So we all know 14th was the last day of Windows 10 support. Turned my Microsoft Surface Pro 3 about an hour ago to be greeted with a blue screen and a message along the lines of Secure Boot policy has unexpectedly changed and bitlocker needs unlocking. Looked in my password database but I have no record of a bitlocker key. After a bit of Googling I found there's a way to get this online from your Microsoft account, if the PC in question uses the same Microsoft Account. It did so I'm up and running again.

What caused this? Well, even though support finished on 14th the Surface Pro did 2 updates yesterday (17th)! KB5066791 and KB5066747

If you don't know your bitlocker keys you can run the following command from a privileged Command Prompt. manage-bde -protectors C: -get

 

[picnic]

Possibly. I've had the device since new and never had this issue until today. The Surface is a Microsoft Device and, strangely, Windows updates are controlled by Microsoft. Microsoft want me to upgrade and throw away a machine that still functions just fine? As I said coincidence?