Might be bad....
This could be a bad thing if they treat the C+ certificates like RUCs; in that only certain routes qualify/limited inventory. I could see certificates not being applicable for any international flights, LAX-JFK, HNL-ATL....etc.
To take this one step further, in the future, they may make C+ seat selection like complimentary first class upgrades at T-5d, T-3d..... It is based on available W(Up) inventory. Which we all know means near zero chance of getting it on the flight you want. I have a feeling they will slowly and quietly take away complimentary selection of C+ seats all together for PM/DMs also, and just give them more certificates. They will end selling discounted C+ seats till T-1hour versus a complimentary upgrade.
If they want to squeeze more money out of people, then the above will happen.