A choir member from my former parish e-mailed me asking my advice on whether she should contact the diocesan office of worship. She is devastated that the pastor has insisted on the choir's reception of Holy Communion in the choir loft from an extraordinary minister. The choir no longer has the option of receiving from a priest or under both species. The pastor's reason is that it unnecessarily lengthens the Mass when the choir goes to Communion downstairs. I don't want to argue about whether or not lengthening the Mass is necessarily a bad thing, but I believe the pastor is mistaken. When I was there, the Communion ministers at the front of the church (where the choir was receiving) generally finished one to two minutes before those at the middle of the church, regardless of the number of choristers receiving.

I don't know that anyone has a right per se to receive from an ordinary minister versus an extraordinary minister, but the GIRM says the following:

283. In addition to those cases given in the ritual books, Communion under both kinds is permitted for:
a) Priests who are not able to celebrate or concelebrate Mass;
b) the Deacon and others who perform some duty at the Mass

Norms for the Distribution and Reception of Holy Communion under Both Kinds in the Dioceses of the United States of America:

46. It is the choice of the communicant, not the minister, to receive from the chalice.

GIRM 103 says that the choir and other musicians exercise a liturgical function. Is this equivalent to "performing some duty at Mass"? Is it legitimate (i.e., necessary for "the orderly and reverent distribution of the Body and Blood of the Lord" [norm 28]) to prevent the choir from receiving Communion under both species at Masses where the rest of the congregation is permitted to do so?

Finally, it should go without saying that sending an extraordinary minister up to the choir loft necessitates the use of an additional extraordinary minister. "When recourse is had to Extraordinary Ministers of Holy Communion . . . their number should not be increased beyond what is required for the orderly and reverent distribution of the Body and Blood of the Lord" (norm 28).

There are older discussions about the best location and procedure for the choir's reception of Communion here, here, and here. I don't wish to revive the discussions in those threads or spark a debate about reasons for or against receiving under both species in general. My specific question is as follows:
Is it legitimate to deny Communion under both species to the choir when the rest of the congregation has the choice of receiving from the chalice?