Will the analog out ever disappear?

Possibly, but unlikely, because it not dependent on ever-changing digital technologies. Your CruelKiller Dominance Mk. II might have the latest codecs, or ancient codecs, but it can output analog, it will work with anything else. Unless there's ever a truly universal digital standard, having an analog out seems to be something that will perpetuate.

Most new HDTV's do not include an analog out. Only a Digital Optical out.

Never! I still hang on to my Edison was cylinders, but I do admit that finding a repair man is difficult.