Have you ever read through the rules for every use of the word "Immediately"? I recommend doing it with the pdf's search function.
Just looking around, I don't really see a rules jargon meaning for the word "Immediately." I'm not sure it has a meaning, really, other than as an English word for, "before the otherwise normal next step."
Did you know that Quick Cast actions must happen immediately before or after a friendly creature action, but Wizard's Tower activates only "before or after"? If you wanted to take that hyper-literally you could propose that this means that the Quick Cast action must always be between the Wizard's Tower action and the Creature action, and not the other way around. I think you'd be wrong, though.
Also, all Enchantments may be revealed immediately between a creature's movement and it's quick action. I
I don't think that I should be able to disrupt a Charge Bonus by revealing an irrelevant Enchantment in that moment and then claiming that the attack wasn't immediate.
So the only question left is, "Is there something about Teleport Trap that would be especially relevant, when revealed just then?" I don't think so. If it was being revealed during the attack action (during step 2, maybe) it could work like Divine Intervention, or if it had teleported the attacking creature into a different zone that would also disrupt the attack because the creature would then have to attack a target in its new zone, but I see no rules reason teleport would be a special case here. Teleporting a creature 0 zones in-between its move action and it's attack action doesn't really do anything.
Mage Wars isn't a game with special Charge actions; The spell Charge grants two independent benefits that are unrelated: one for movement (Fast) and one for combat (confusingly also named Charge +1). You can't disrupt them by decoupling them, because they're already decoupled. The use of the word Immediately doesn't change this. Go see what other rules it would break if that's what Immediately meant.
The answer to this question is pretty clearly "No, Teleport Trap can't deny the attack bonus from Charge if it doesn't stop the attack in the first place."
Attempting to draw conclusions from game physics--or anything but the black letter rules--is a privilege reserved for the designers alone.