Black Friday sale… but not phantom upgrade?

I was super excited to see the newest black Friday sale on the game because I have been very happy with it recently, and I would like to give the developers more money if possible.

 I currently have the base game and was thinking about upgrading to the Phantom edition, however on Steam, it looks like the upgrade to Phantom edition is still the full price and is not discounted at all. This does not make sense as the standalone Phantom edition plus game is discounted. The upgrade should also be discounted. Is this a bug? can you please fix and discount?