Questions will keep their required setting at all times, but if a question is not visible, then it won't be required. So, if they're hidden by logic, they won't be required for form submission. However, if they become visible through logic, they will be required for form submission.
If a section or page has logic on it that makes that section or page invisible, all of the questions within it will not be considered visible as it relates to checking if all required questions are answered for form submission.
It all comes down to whether the question is visible.