If a field is disabled, should the accompanying help icon also be disabled? The content within the help does not discuss why the field is disabled btw. The user needs to fill out a field previous to this field to "unlock" it.
Logically speaking, as the help-text for that field offers no value to the user when the field is disabled, you should be OK disabling the icon along with the field.
If, on the other hand, the help-text contained information that helped the user to understand why the field was disabled or helped them re-enable it then, logically, you would need to leave the icon enabled.
I understand that your particular situation falls into the first scenario rather than the second but I wanted to be clear for anyone else reading who may have a different situation.
You could keep it enabled so that users can get a bit more of an idea of what it is and hence how to enable it. It would also satisfy those who are just curious what it is.