I own CoS but my buddy is going to GM, why can't he see the macros?

The subject says it all.  

Hi Alan! Only the creator of a macro can see or edit their macros. Since you are the creator of the game, you are the de facto creator of the macros and can edit them. A promoted GM can't. However, as the creator, you do at least have the ability to give them permission to use any of the game-created macros. They just cannot open or edit them. If he wants to make specific variants of any of the provided macros, there is a handout in the game that gives the text for each and every macro.

To add to what Keith wrote, I strongly recommend using a Macro Mule for macros. Multiple GMs can edit the mule's macros and it avoids a number of issues with the Macro tab macros. 

Going forward, absolutely. But the macros provided in modules are standalone macros and have that editing issue.

Ok.  Thankfully we figured out that the handouts have links to the macros and he can get access to them that way.   We have a mule for the player macros already.  I wasn't looking forward to creating another one.