I was trying to find out how to get my lockscreen to display on both of my monitors rather than just one and I stumbled upon this thread from 6 months ago. In the thread it's mentioned that the request for two+ monitor lock screens to be reinstated was passed along to the team. I was wondering if there's been any update on the progress of this? It may sound like a small problem to have but it makes me sad that Windows 10 took away a feature that I really loved for (seemingly) no reason at all.
I've been resorting to using my NVIDIA surround to treat my two monitors as one but it's annoying to have to turn it off every time I log in (since I find surround mode annoying for watching videos etc). I'd love to just be able to click a button and enable a multi-monitor lockscreen. Looking forward to a fix for this :)