Released at the same time? That could prove to be expensive, but it's definitely better than just getting one or the other.
(Then again if they do release a Doobie Brothers set, then that's really all that matters to me, along with the two Eagles Quad albums. Everything else is lagniappe to me.)
Lotta Quad lagniappe in Warner's vaults, I imagine.. and if box sets of one particular artist are a no-go, Rhino could do Quadio sets on a theme, maybe along the lines of..
1.) Soul/R&B Quadio set comprising of Average White Band, Donny Hathaway, Graham Central Station, Herbie Mann, Spinners, Roberta Flack (11 x Quad set)..
2.) Hard Rock Quadio set comprising Alice Cooper, Black Sabbath, Black Oak Arkansas, Deep Purple, Focus, Souther Hillman Furay Band, James Gang (11 x Quad set)..
3.) Rock & Pop Quadio set incl. Beaver & Krause, Bette Midler, Bread/David Gates, Dionne Warwick, Tony Orlando & Dawn, New Seekers, Seals & Croft (15 x Quad set)..
4.) Jazz, Big Band & Crooners Quadio set including Alice Coltrane, Fats Domino, Duke Ellington, Charles Mingus, Frank Sinatra, Modern Jazz Quartet (12 x Quad set)..
5.) Prog & Experimental Quadio set including Absolute Elsewhere, Deaf School, Kraftwerk, Passport, Stardrive (Robert Mason), Frank Zappa (7 x Quad set)..
6.) Country,Folk & Singer/Songwriter Quadio set including Gordon Lightfoot, Joni Mitchell, Judy Collins, Maria Muldaur, Jackson Browne, Randy Newman, Ralph McTell, Carly Simon, James Taylor (17 x Quad set)..
Then a follow-on question would be (going back to individual artist/band Quadio box sets) regarding IF Warner owns the rights to Capitol acts like
Al Green (with 8 x Quads in total; 7 albums + 1 Hits comp)
..and who now owns the Grunt catalogue?
Would make a nice 12 x Quad album Boxset..
Hot Tuna (5 x Quads),
Jefferson Airplane (3 x Quads),
Jefferson Starship (3 x Quads),
Kantner & Slick (1 x Quad)..
..and Arista Quads would come under which label now?
(Eric Carmen, Barry Manilow, Melissa Manchester, Tony Orlando & Dawn Hits, Outlaws, Brecker Brothers.. 9 Quads in all? Make a nice box too..)