anything's possible when it comes to the music business, it seems.
Although (correct me if I'm wrong, of course) but I don't recall most of his 70s catalog ever being released on CD by CBS/Sony, but instead some of them were licensed to small reissue labels like Real Gone and often released as cheapy-twofers.
While presumably Columbia still controls those titles, as they have continued to release Mathis compilation CDs over the years, it doesn't seem anyone is THAT precious about them. I suppose it could be Johnny has some say and has some objection to the quad mixes (although he certainly seemed OK with them at the time as so many of his titles were released in quad) but it also seems logical that he'd like see his catalog get some new life and maybe even make a buck or two in the process as well.