Is it a correct specification that the security context is newly given to a file when its file is restored in rescue mode?

Issue

• We backed up a system whose SELinux is unavailable by dump command in rescue mode.
• And then, we restored the system to another partition by restore command in rescue mode.
• As a result, files which had never obtained security context got security context newly.
• Please answer the following questions.
  1) Is this a specification?
  2) Is there information changed except that the security context is given if it is a
  specification?