What's the recovery time for excision of bilateral axillary breast tissue? How restricted will arm movement be and for how long?

You'll be best off addressing your questions/concerns directly with your plastic surgeon.  Much will depend on exactly what operation is performed, how you are progressing, and exactly what activities you wish to return to. Best wishes for an outcome that you will be pleased with long-term.

Depending on the amount excised and incision size, you could be up and around, driving in 2-5 days. You should be able to lift your arms to dress and shower right away. Heavy excercise should be avoided for 3-4 weeks

Removal of the axially breast tissue is a fairly straight forward procedure and the recovery will vary, but in general most patients can go back to most routine activities with in a few days, but permission to do exercise will vary from surgeon to surgeon.