Sometimes, situations necessitate that a player really does have to get out of a game that they thought they had time for. Emergent new gameplay in real life, for example. Or (this happens often, including in this game) when a player inadvertently learns information about another slot in the game that they shouldn't have.
In either situation, rather than ruining a faction's chances and ruining a setup that a mod has waited months to run, it seems extremely clear and straightforward, and it has always been the rule in DG, that the affected slot should be replaced.
I've replaced into 30 games (conservative estimate), more than anybody else on the forum probably, and I've often had a more enjoyable time playing those games. But sometimes it's also a situation where the replaced slot was already on the chopping block, and replacing in is moreso a courtesy to keep discussion going rather than shutting it down with a modkill. I actually came to AiB and then to Smashboards specifically because I was asked by friends to sub into Mafia games. I don't play Smash.
Now, granted, Soup didn't have an emergency, he just wanted out. But that still shouldn't garner a modkill and disrupt (in a game this size) 20 peoples' game. Typically we ask players to make it very clear that they want out, and because he didn't do that, the mods should have followed up with him. Granted, the Day length is short enough to make doing that and then finding a replacement tricky, given the amount of time.
The DH situation was more nuanced, but when it has happened in the past, it has always resulted in a single or double replacement depending on if information went in one direction or both directions. Again, preserving the game is a lot more important than making some sort of weird example of players. It is a very rare case that I'd opt for a modkill over a forced replace, and I can't even think of a reason to do so aside from the inability to track down a replacement (or posting your PM to multiple people, thanks DH).