Unable to reset "revealidentities" in course reset

When a user is doing a course reset to prepare a course for reuse, any assignments using blind marking are left with the real student identities revealed, and there is no way to "re-hide" them.

This effectively means that blind marking assignments cannot be reused.

It would be useful if either:

• there were a setting in the "assignments" section of the course reset to explicitly allow student identities to be hidden again, or
• for blind marking assignments, when both "delete all submissions" (under assignments) and "delete all grades" are chosen on the reset form, the student identities were automatically hidden

This is related to, but not the same as, issue MDL-43796, which is about changing this setting on backup / restore or duplicating activities. There is one big difference though - with backup and restore it's easy to see scenarios where you may want to transfer this setting as-is, but it's very difficult to think of a scenario where you would reset assignments for reuse but not want to hide the student identities again.