I think its weird to even use such a term in a different context to begin with. Its also generally pretty inaccurate. Many such primary/secondary or parent/child relationships in tech exist either for redundancy or for determining priority/sort order, which isn't what a master/slave relationship would do in a slavery scenerio. About the closest equivalent is a manager/worker relationship, which again is more accurate to say manager/worker because it is not a hostile relationship between the worker nodes and the manager node.

So in short:

1. Master/slave is inaccurate. Inaccurate terminology leads to confusion, and confusion leads to inefficiency and time waste.
2. Changing from Master/slave to something else is a relatively easy change to make
3. If there's even a chance that it leads to a more inclusive working environment that's even better!