The disc will only have Destiny on it. (Destiny)

by Xenos , Shores of Time, Thursday, August 13, 2015, 17:50 (3231 days ago) @ Cody Miller

So, correct me if I'm wrong, but it looks like if I want a disc it will cost me 60 bucks instead of 40 for the digital. Right? There's no 40 dollar disc version?

Correct, but there won't actually be a "disc" of The Taken King, it'll be a disc of Destiny, with codes for all of the DLC (including The Taken King).

Source

They did say something about something for people who already ordered the DIGITAL Collector's Edition (which they haven't yet told us what they are doing for them), but I don't think they said anything about the people who own physical copies of any of it. Probably because you can still cancel your physical pre-order, while you won't be able to (without a lot of pain and possible yelling) cancel your digital pre-order.