I can't believe there's been days and days of discussion on this already.
I think if there are going to be variant games of any sort then they need to
be labeled as "variants" when players sign up for them so they know what
they're getting into. Unless something in the program clearly states
otherwise, I expect the games I sign up for to use the published rules.
If I've played the game before, then it helps me to prepare for it and to
know how to play; changing the rules deprives me of that and may mean that I
won't enjoy the game. Strange as it sounds, some people actually like
playing games the way the rules are written.
I ran a bunch of Zombies!!! demos this year. There are many variants for
Zombies!!! some of which are very popular and some of which I like better
than the published rules, but the demos ran with the published rules because
only those rules give the players common ground in understanding the game.