So... hearsay? Hearsay about the word of a freelance novelist who did not actually write or edit the book in which Janeway was killed, and who is neither the editor nor the author of the Star Trek: Voyager novels?
Not exactly hearsay when you are hearing the report from a reliable witness first hand, as in my case. I have personally spoken to one of the witnesses (actually I can contact at least two of them). This person is reliable and someone I trust.
No, that's still hearsay.
So to finally satisfy you and your doubts:
It was ME (the owner of the Bring Back Janeway Facebook group) who talked to David Mack at the book stand of German Trek lit at Fedcon XX in Dusseldorf 2011.
I'm grateful that Mr. Mack took the time to frankly answer my questions about Janeway's return. I have a different view on those things than David Mack has, of course, nevertheless we were able to manage a businesslike talk and listen to each other.
With me there was a friend of mine who took this photo of me with David Mack and another German Trek fan as well as the sales assistent of the book stand where I bought the Destiny trilogy which David Mack signed personally for me.
I published a short report about my talk to David Mack on different Voy boards in English and German after Fedcon. So there is no secret about it.
Quod erat demonstrandum.