In the 2.7 Pro help it states :
Enable attribute validation to restrict attribute edits to values that satisfy the validation criteria imposed on a field. Examples include domain values and fields that do not allow nulls or empty field values.
I have that checked in my options:

And I have a domain controlled field in feature class I'm working on. However, I can use the field calculator to enter any value I want in that field:

What does that option do?
Secondary question: Is it possible in Pro to access the domain values in the field calculator? For example, I am updating the address type to 45 selected records. I can go through each one individually, or I can use the field calculator (and misspell a domain value).