As stated by 343 Industries in a recent blog post on Halo Waypoint
“When we last left off, we let you know that we had heard the feedback that some of you prefer a physical disc instead of a digital copy, and that we were exploring options. Today, we’re able to confirm that for those who would like a physical disc, we’ll provide an option for fans to exchange their digital copy for a physical copy at no additional cost. We’ll get into details as we get closer to launch, and we’d like to once again thank you for the feedback.”
So this means for everyone planning on getting a Collectors edition, you have a disc to put in that fancy SteelBook case you are getting with it, of course if you’re not into discs and just prefer going all digital that option is 100% still open to you. Either way it seems like you’re going to get your disc or code to pre-load with your collectors edition a week early as the collectors edition will be releasing a week before the launch date of the game. The early release date was likely to give people who ordered the collectors edition time to pre-load, it should be interesting to see how they handle distributing the physical discs and if people will be able to play using them early.