We recently had an issue with an HTML block changing a link that we wanted to go to another course during restore.
It seems to me, that the software should work like this:
if the link is to an internal file in the course, (an image, doc, ppt, etc. that is in the course files area) - the link should change to the new course on restore. BUT if the link is to anywhere else, another web site, another course in the Moodle system, etc, it should not change on restore.
We have a lot of links between courses - for a student to jump from course to course via the link - and we also restore the courses each term, so having to re-link all these is a pain!