We are using organization to ensure that some users can see all issues in a service desk as members of the organization and some users can only see issues they submit. I am currently adding the organization via workflow post function on issue create.
We do not want the user to be able to change the organization at all.
However, on the portal, when you are submitting an issue and you are in an organization, you get the option to share or not share with the organization:

Also, you can stop sharing with the organization once the issue is created:

Is there any way to disable or hide these elements on the protal?