Yes, once I figured out what was going on, I used it. Here’s a thread where I figured it out- "Edit Active Part Only" Solo Editor Function Problem_Cubase7 - #3 by steve - Cubase - Steinberg Forums
Here’s a thread expressing dismay at losing the new functionality- Solo Key Editor Cubase 7.5 Works Differently - Cubase - Steinberg Forums
As feature requests go I think this is a solid one…