Only to keyframe opacity(?) of a strip that is set to alpha over, and is placed above the previous shot.
You have to remember that Blenders VSE is first and foremost an animation editor. So it expects you to produce and lock the audio, not perform audio mixing in the timeline. Sadly performing a meta strip (combining strips into one strip) will not allow you to affect the audio inside.
The Sequencer addon, extra tools (I think), allows you to automate a fade function to multiple strips at once so you could select video and audio then perform this fade function.