A bit more info, for those interested. I think they will probably do a run of non-lock 340s, but that is just speculation on my part. They did the 642 because it is one of their best sellers, and a large distributor asked for a run of them without a lock.
I have a few S&Ws with the key lock. I won't let the lock stop me from buying a new S&W. Price is what usually stops me from buying what I want. I can only afford so many. The lock is very easily disabled, if it bothers someone.
I have never had one lock-up on me, but I have been present when a 329 locked itself in another shooter's hands. It happenned twice the same day. I have fired many,many rounds through S&W revolvers with the lock, both handheld and in a Ransom Rest, using the heaviest loads commercially available, and never had a lock failure. I carry a 342PD daily, everywhere, and have for several years. I have no fear of the thing locking itself. However, if I was carrying a 329 for protection, I would disable the lock.