As we all know, Anet makes the majority of their income from Gem store, where people purchase gems to buy skins etc.
To monetize WvW more and bring in money to fund new WvW features it would be good, in my opinion, if Anet made Call of War buff a "premium" buff.
For $5/5€ one would get (for 1 month):
+25% WvW Reward Track Progress
+50% Magic Find
Access to Armistice Bastion
Your equipment cannot be damaged (at this point, it should really be removed anyway)
Would it break anything? No. Would it maybe bring in more players to WvW? Perhaps.
I see no downsides to it.