Probably a discussion for the deep harmony thread 
But yes - I seem to get a bunch of idiotic responses from alexa with variations of next/skip track, skip forward etc.
Edit:
I have updated the topic at Roon Extension: Deep Harmony - rich feature set for Logitech Harmony with some simple Alexa command that seem to work.
After a couple minutes of fiddling, I have Alexa Play/Pause/Mute/Volume Up/Volume Down/Fast Forward working. for anyone in this thread - this is using Alexa with Logitech Harmony and the extension referenced in the above link.
(@Moderators - apologies if this is making a mess)