When using PasswordParameterDefinition , "Rebuild" option doesn't persist the default value configured in Freestyle Job configuration as "Default Value". When running new Build, default value is used as expected. I've double checked the configuration on Master and there is encrypted default value.

Steps to reproduce:

1. Create simple Parametrized Freestyle job with parameter of type: Password parameter and populate with default value, e.g. test
2. **Configure Build step to echo your password parameter 
3. When you will run build for the first time, everything looks as expected
4. When you will rebuild first build, there won't be any password populated.

This looks to me as bug. We have specific use-case when we are utilizing Rebuild a lot.

Let me know if any other info needed to be provided.