If its just bleach they are using then no a skin test won't be done. But the consultation should be thorough enough to find out previous processes etc... Inc strand testing.
I done a colour correction Saturday, but as it was my aunt I knew what she had done over time so I didn't need to test, after a mild bleach bath I always use a porosity regulator like 4x4 to make sure the over colour is even.
I'm no top end stylist yet, but i do make sure my consultations are extremely thorough as in my eyes te consultation makes up 50% of the final result and happiness of the client. Xoxo