I can't answer that question specifically because I honestly don't know (nor could I probably say exactly even if I did) but the nature of the production process means that he's constantly got a lot of irons in the fire, and things are released as they come to fruition rather than scheduling a release of some specific titles on a specific day, and then trying to get the work done to meet that deadline. There are so many factors that can delay a release, from missing master tapes to various legal and approval issues, to pressing plant backlogs that the answer to the question "how long does it take to release an SACD?" is the old British expression 'how long is a piece of string?'
Again I haven't really worked on the classical side of D-V, but on the pop side it's been as quick as 6 weeks from when I've been told they got a license to when it was in your hands (Earth, Wind & Fire 2fer) to 8 or 9 months (I wrote the liner notes for Derringer and the Guess Who
Road Food/#10 the summer before they were released) to even longer, as is the case with a whole bunch of titles I worked on with Paul, D-V's artwork guy in the spring and summer of 2020 that still haven't been released.
Well for as much as I know about the pop side of quad from first-hand listening experience, when it comes to classical it's more based on what I've read and what I've heard from others. I'm not saying all the EMI classical quads are ambient - I think, for example, one of those Grapelli/Menuhin LPs is discrete - but it's my understanding that most of them are ambient surround.
One rule of thumb when it comes to quad for me is that you really can't judge the discreteness of a mix from an SQ decode. No matter what decoder you use, there's always some "collateral damage" - that is, things from the front speakers that leak, or even worse, are pumped into the rear channels by the over-zealous logic circuits of a decoder. The same goes in reverse, sometimes SQ encodes are so bad that truly discrete albums are so poorly separated that you can't totally tell what the mixer was trying to do, or if what you're listening to is some kind of fake quad. That was definitely the case for me with The Isley Bros
Go for Your Guns SQ LP before I heard the Q8, and especially with the O'Jays
Survival and
Family Reunion before I heard the revelatory D-V SACD from the discrete master tapes. If
@4-earredwonder reports that his collection of digital discs from the discrete masters of these albums are ambient I'd put a lot more credence in that than what an old SQ decode may or may not be doing.
Maybe a question for
@ubertrout or
@humprof, but if EMI/Angel's quads are primarily ambient, does it make CBS Masterworks close-mic'ed/discrete classical quads somewhat unique? I know there were some other labels doing discrete quad recording like DG (is that where the Pentatone SACDs are sourced from?) but it seems like the other majors favoured ambient surround to this classical neophyte.