Happily, this attitude seems to be in decline. One member of an ensemble that is not of the standard variety told me that through several personnel changes, difficult as they were, there had been no evident effect on the trajectory of their bookings. In fact, there may be extra interest in the performance, and even a special excitement from presenters about getting in on the initial tour. Letting people know If your group's name isn't a household word, the most convenient time for a change to become known is after most decisions have been made about bookings for the following year. Presenters looking at you for future seasons at the beginning of the new cycle will know that by the time their booking would take place, the new member will have been playing with the ensemble for at least a year.
Ongoing communication is essential.
Don't assume the change doesn't make a difference to me. Keep me in the loop. I know these things happen and why. I believe her view on this topic is typical. If you have a large-scale university residency, you will want to waste no time sitting down and talking with those responsible about the change.