I can sympathize with your hurt and upset, particularly if the pastor acted tactlessly, which it appears that he might have if he insisted that the keyboardist be “dismissed.” The keyboardist could possibly have been asked to play another, more appropriate instrument, such as a piano or organ. Certainly the pastor should have been more considerate toward your concerns and could have tried to maintain communication with the group to see if the problems could be resolved.
I wonder if you have given thought to the pastor’s concerns. My guess is that he is trying to elevate the quality of music at Mass. While you are to be commended for working with him to the point of the dismissal of the keyboardist, there are some attitudes within the group that could be improved. I am thinking particularly of the ideas that volunteerism means that the choir should be independent of the pastor’s authority, the apparent belief that the keyboardist was “excluded” from Mass, and the suggestion that the choir “celebrates” the Mass.
Perhaps if there had been better communication between the pastor and the choir in both directions, the pastor might have acted more diplomatically and the choir’s concerns might have been addressed to its satisfaction. If the group is interested in healing, as distinguished from brooding over its injuries (both real and perceived), then I recommend that the group arrange for an appointment with the pastor, in which the members can share their concerns and ask him to share his.