I would think it makes more sense, in the vein of the books linked above, to have the lists/interviews curated by composers & performers, rather than critics/musicologists.  Or perhaps some combination of composers/performers/musicologists/critics ...?

Aaron, for the type of book you're suggesting that might indeed make sense. But I think the original subject of this thread was a potential 'sequel' to the R. Murray Schafer and Paul Griffiths volumes of interviews. Schafer was admittedly a composer, though arguably less remembered as one today than as a writer/interviewer. Andrew Ford has also produced a similar book on Australian composers, in which he doesn't really talk as a composer, although I believe he is/was a composer as well as a journalist. Griffiths certainly isn't a composer.

I'm not trying to say we can't go off-topic (or branch out from the original suggestion), and I think what you're talking about could be a fascinating book in its own right, but I'm still curious to know whether you think a single book of around 20-25 composers interviewed by a single critic/musicologist would be worthwhile today.

Yes, I absolutely do think such a book would be worthwhile.  (I've stayed out of some of the specifics of the discussion b/c it's all of course about British composers and British journalists/critics/musicologists, and, while I spend a good bit of time over there, I'm too much of an outsider to really contribute effectively to the various lists that are developing.  I certainly have my preferences and biases, but I'm mostly keeping them to myself for the time being.)

a few ommissions:
Peter Wiegold
Michael Berkley (fantastic programming at Cheltenham)