I get the impression that there are several reasons, and that these reasons are not insurmountable.
1. BGO has had Edgar & Johnny Winter albums out on CD in the UK for many years - included are two-fers, etc.
2. Their album catalog might not be big sellers at this late point in time (not very many hits to report)
3. AF stayed away from "They Only Come Out at Night" (three hit singles) because MFSL had it out on SACD (20 years ago)
4. Which albums should be considered? Just the big hit album, or an additional? Two Johnny and two Edgar albums? .
So it looks like some risk is involved financially. But I think there are reasons we might actually see these come out on SACD with quad layers, and here are the reasons.
1. Tapes are likely in order and in good shape
2. These albums do fit well as two-fers (two albums on one quad SACD)
3. The sales and careers have cooled off enough that licensing costs might not be so prohibitive.
4. They are Sony controlled, and DV has a good line of communication obviously.
5. The albums are solid musically, and quad mixes are strong.
6. The albums that are of top choice quality, and titles available, is not a bottomless pit. These albums are standing out as obvious choices when "quad" rock titles controlled by Sony are considered.
7. If Rick Derringer as a two-fer can happen, two-fers of four Winter titles is definitely on the table.
Just remember if Cherry Red has the UK license on the Winters, then there is no chance that D-V would be able to issue any of them until the Cherry Red agreement expired. It's just business!