Just for the fun of it, I went back to see what ShadowGram has said on the subject and what sort of phrasing they've used.
First it was announced as "will most certainly":
From November 6th's Update 227:
SG PREMIERE-ANNOUNCES:
DS composer "Bob Cobert's original theme will most certainly be integrated into the musical score of the new movie, though the retired composer will not be directly involved."
But then it was downgraded somewhat to "will likely":
From February 28th's Update 234:
Robert Cobert's original theme will likely be integrated into the production also."
Then it was downgraded further by saying it "may" be used:
From May 14th's Update 239:
((SG previously announced Robert Cobert's original DS Theme or other musical elements may be incorporated into the movie score))
(And that one also mentioned that other musical elements could possibly be incorporated - probably not a smart move in retrospect given Elfman's most recent comments.)
But then it was once again said that it "will" be used:
From July 23rd's Update 243:
SG previously reported Danny Elfman is scoring the movie and Robert Cobert's classic "Dark Shadows Theme" would possibly be incorporated. SG now updates that Bob's memorable Theme will be part of the soundtrack.
And the status hasn't been mentioned since. However, it would certainly seem that things have indeed changed since then. And, of course, it's also possible that SG's source shouldn't necessarily have been as certain as they were when they passed along the info...
198 days 11 hours 11 minutes 27 seconds until the day the Depp/Burton Dark Shadows is released(ET)!!