I'm not going into specifics because its to do with a gaming hobby.
If you and a group of friends had been planning something very specific, and then everyone else involved decided to go ahead with it the one week you're not available, but you ask to be left room to add your contribution at a later date (which they agree to), but instead they cut you out of it completely, would you be justified in feeling hurt and left out as if you're basically completely unimportant?