At this point, I think it is wishful thinking with a big dose of hope. Most of the sources (that is Ed Pong and Bob Attiyeh) are doing their own recordings - so they can't afford to do large scale pieces, the ones you are most interested in having. Tape Project, aside from two early Decca albums which they got with their relationship with Winston Ma, have only released Reference Recordings classical issues, which themselves are quite limited in number, especially ones recorded in analogue. The best realistic current hope is Horch House, which has been able to get licenses for some major works (I have Mahler's 1st, and the very fine Herman Prey Mozart Arias albums licensed from Eterna and the Steinberg Also Sprach from DGG). Their earlier symphonic releases (which I also have) were with a lesser regional German orchestra where the licensing was easier, but the playing not as compelling.
Anyway, unless Sony (RCA, Columbia) or Universal (Decca, Philips, DGG, Mercury) or Warner (EMI) open their tape vaults to an interested company with enough capital (hopefully Chad), I don't see enough of a flood of classical orchestral tapes being available. We have to remember that all the big companies stopped doing analogue recording 30+ years ago. If Chad were able to make available tape copies of the RCA Living Stereo albums he has and is planning on releasing, that certainly would go a long way toward the collection you are talking about.
With my new ATR-102 arriving shortly, I am going to experiment with recording some of the stereo DSD files from downloads I have (particularly the 256DSD) to see what they sound like on tape. Not sure why they would sound better than the original files, but the experiment will be easy enough to do.
Larry