I already know it. Your medical files are otherwise secure, but if you join up, the acting Legion Leader has full access to any information from Medbay's power scans. The Medbay staff should've disclosed that to you, but sometimes there are slipups.

But if you want some discretion in your teammates not knowing it, it can stay undisclosed. For people with powers that involve depowering others, there's a definite battlefield advantage to keeping knowledge of them limited. Less Legionnaires for enemy telepaths to potentially pull the information from. More potential for a surprise ambush.