Actualy Vulcans don't need to mate to prevent death when they have their Pon Farr, fighting (such as was done between Kirk and Spock is enough. There is also an epis of Star Trek Voy that highlights this. So them fighting in the last strip COULD have fixed the problem. However it might be funny to see a little Dilbert show up in about 9 months or so...
HERE, the whole Pon Farr thing was never resolved. There was no returning to their "spawning grounds, or doing anything in order to serve their primal needs. It just ended, and that's sorta messed up. I'm kinda disappointed in how it simply ended.
I don't know where you get "... if Vulcans don't mate, they die..." from. Spock did not mate in the original series, so if anything it would have been something made up and added later.
If Vulcans don't mate, they die. So either there's a difference between Vulcans and engineers or they did the deed. Either way we're left hanging wondering which it was. I hate inconclusive endings. It's like a bad European film.