Profiles, Change Sets and New Custom Fields

Question

I have a question about change sets that seems basic but I haven't been able to find a definitive answer. Essentially, I have a situation in which an admin wants to deploy 3 new fields from sandbox to production. They have created a change set with these three fields added as components and ALL of our profiles in the 'Profile Settings For Included Components' section of the change set. Am I correct in saying that ONLY field level permissions related to these three custom fields will be updated in the production org?

This is my understanding though I have never been able to find definitive documentation on this. There have certainly been in these profiles in production since this sandbox was updated and I fear reverting or altering these changes. I've certainly looked at this document but it's a bit confusing. Any help, guidance, other documentation would be helpful. Thanks!

Answer 1

I can say from my experience that adding a profile and/or a permission set will only update components included in the same changeset but like you I've tried to find offical documentation explicitly stating it before (in relation to this question: Can including a profile in a changeset remove a permission/FLS?).

It's not especially clear but rereading the document you linked does imply it with this line (column behavior, second row):

Included permissions and settings that require supporting components