shoulda woulda cooulda...
as i recall, Pleasance wasn't their first choice for Blofeld in YOLT (i've forgotten now who was, but it's on the "Making of" documentary on the disk, i believe), but he was a last-minute fix when somebody else couldn't do it... but then when they went to do OHMSS, they needed someone more able to do the physical scenes, which is why they went with Savalas... then for some reason or other, Savalas wasn't available for DAF... though i still can't justify in my mind why in the world they went with Gray, of all people...
can't say that i've ever heard that... wouldn't make sense the way they did it, anyway, since in the pre-credits, Bond is searching so hard to find Blofeld to get his revenge for Tracy's death (oh, how i wish they'd used the revenge element for more of the film!), and it couldn't have been TOO FAR back in time, because Bond knew what Blofeld looked like, and he never saw Blofeld before YOLT (though i still can't figure out why Bond knew what Blofeld looked like, since Gray's appearance was so much different from Pleasance's or Savalas's, and even his voice was considerably different, since he now sounded British when before it was difficult to tell...)