I wouldn't say the craft of conductor (or any train crew) for that matter is in danger because of too many people. They don't have enough these days. The only thing I would be worried about is if the railroads will cut the craft. BNSF is trying too, but the union membership vote is looking like it will be a no and legislation could be enacted requiring a conductor and an engineer on all freight trains. If they DO cut the job, most class 1s will probably follow. I doubt that would last long because a lot of people will get hurt. However, I'd say that most regional rail lines and shortlines are going to have conductors for another 50 years, so if you hire on a class 1 and get qualified, you shouldn't have too much trouble getting on a smaller road. It seems like they may not be as good but some shortlines are M-F operations, good pay, and some are union too.
I'm not an expert on the subject, but I've read a lot and have listened to a lot of guys because once I am done with school I want to enter train service. Crossing my fingers that those jobs will still be there.
"Clear back three cars to the Admiral"