I believe GWWC do include ‘income you have sacrificed to do direct work’ in their pledge. (Correct me if I’m wrong, GWWC folks.)
This does not seem like a very plausible interpretation of the actual words in the pledge, and the GWWC FAQ is quite clear on this matter:
How does working at a nonprofit or charity change my pledge?
While we think direct work at a charity or nonprofit can be extremely impactful! However, your pledged amount does not change depending on your workplace or occupation. Those of us who work for nonprofits, even if we left higher-paying jobs to do so, still donate our pledged amounts.
If your giving pledge is preventing you from doing more impactful work then it might be appropriate to resign from your pledge. Read more about this in “How permanent is a giving pledge?”.
This does not seem like a very plausible interpretation of the actual words in the pledge, and the GWWC FAQ is quite clear on this matter: