No they will not be abandoned. They are still very much there. The same way the Galaxy S and S II are still there even though the S III has been out for a while. They will be lower priced and budget handsets.
It's a very very stupid naming idea. The One X, One S, One V, etc. are part of the "HTC One" series. Guess whaht? That's also the name of this phone. I swear these Asian companies need to stop naming things on their own and actually consult a person who speaks English natively. The stupid as hell names are always on Asian products, because they have big egos and think they can speak and understand English since they were taught in school and can manage business relations, but in reality it is still a second language to them as foreign as any and they don't have any of the sensibilities. Nintendo Wii anyone? They have a whole army of white people doing PR and sales spread across their offices in western countries, yet they never bother to consult even one of them over it, and those white people are sure as hell not gonna speak up for fear of losing their job. They aren't very high up on the food chain of an Asian company. When Asian people name things with English words, or god forbid latin or some other western language, they do it based on how KEWL it sounds to their Asian ears, or try to convert some deep, singular Asian character into it's English equivalent. That's probably how HTC One got its name. Not only does the "ONE" not translate well to mean anything special in English, it just sounds stupidly simple, and completely impractical and confusing as far as searching for the damn thing on Google or NOT confusing it with their existing product line. Why they keep on making names that are hard to search online for or differentiate from other products, I have no idea what they are smoking. And you can't call me racist since I'm Asian.