I guess can see some sort of merit behind this teleportation thing, but I also feel it seems awfully artificial and contrived. If it is supposed to be a cure for stuck zeds, the answer to that is simply better pathing and play-testing before a map goes live. I can remember several of Epic's maps that shipped for the various Unreal Tournament games that had some very glaring bot-pathing issues, and everyone who has even a little time playing Killing Floor has learned zeds can get stuck, and just where that happens. There really is no excuse for this. If you can't get the pathing to work, then you alter the construction of the map until it does.
As an "anti-kiting" preventative, teleportation feels just cheap and lazy. I think it does break whatever immersion a player has invested in a wave, and, other than a Scrake or Fleshpound, if people want to prolong a wave to scoop-up whatever ammo and equipment is lying about, any other single zed isn't likely to curb that behavior very much. So, what is this really accomplishing?
Actually, if it is a matter of only a single player being left after the rest of the squad has died, perhaps as one of those dead players, hoping that a teammate can cap that final 'Pound or Scrake, I WANT the remaining survivor to be able to use the environment effectively, and confidently. Especially if he/she is low on ammunition and/or armorless. To have that player, on let's say, Wave 8, walk into the warm embrace of one of the big guys, not because of any tactical misstep on the part of the player, but due simply to some totally implausible act of teleportation? Well, to me, that seems like a mighty lousy way of ending a game.
Since the traders are apparently just electronic kiosks in KF2, maybe if people are obviously delaying the end of a wave, for whatever reason, the location of the trading kiosk scheduled to open should start to change in response. This probably wouldn't penalize a sole-remaining player too much in the situation I outlined in the paragraph, above. (When you're dancing with Death as a sole-survivor, the trading location isn't that big on your list of priorities.) But, in any other case, it would otherwise make it in everyone's benefit to quickly hunt down and "off" that last zed, because if that doesn't happen within X seconds, they'll discover the active trading kiosk has just moved 150 meters from where it previously was scheduled to open.
The way it stands now, I'm for removing this teleportation dynamic before the game goes Gold.