The maintenance script `importCheckUserLogs.php` is a maintenance script that would have been used for the now declined task T29807 to import very old (pre-2006) checkuser logs to the `cu_log` table. In T29807, it was discussed that the logs are likely lost and now gone. Therefore the task was declined as nothing could be done to actually import them unless someone finds them at a later date (which is unlikely IMO).
As such the maintenance script used to parse and import the pre-2006 logs is no longer going to be used for WMF wikis and I would argue has no use for third-party wikis in 2024 / MW release 1.42. I would argue that the maintenance of this script is not worth keeping it around (see T352715 / [[ https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/980059 | 980059 ]] as an example of this maintenance). If wikis need to use it then they should use it before upgrading to a newer version.
For example:
# If T309999 is implemented, this script would need to be re-written to import data to a different table
# If T190666 is implemented, then the script would need to be modified to store the an empty comment as the check outcome