When I signed to Atlassian, I got this message:
"You have successfully signed up. If you forget your password, you can have it emailed to you."
IF Atlassian can email me my forgotten password :
It means Atlassian is storing my password in clear text:
Be aware of not re-using a password here
Should Atlassian be compromized, all account passwords could be exposed
This is not a Minecraft bug - however I did just test for the sake of curiosity. They do not email your password, merely a link so you can reset the password. Please use the contact admins form in future.