I think perhaps this is a little OTT. Every one is entitle to their own opinion, meanwhile unless LE states that they believe she is deceased, such as in the case of O'Brien/Liknes even with out a body, then it would be entirely reasonable to assume that there is the possibility that she could still be alive.
Isn't the point of discussing these cases to come at it from every angle. Not one single person here personally knows Shannon Burgess, so therefore does not know one single thing about her life leading up to the day she was last seen. Who's to say the four days spent in Edmonton weren't prepartion for an upcoming move there.
There are plenty of women who have snapped and walked away from it all. Then there are the women who were presumed dead and left for dead because how on earth would they still be alive. Well, we as the people who are still around and are actively concerned for these victims owe it to them to explore every single option, be it death, be it an alias, be it anything.