Bug: Noticed this as part of Trust and Safety investigation, but previously, with @Paladox' enhancements to the removepii.php maintenance script, certain CheckUser log actions relating to deleted and anonymized users were deleted. Now, though, as the old username is not renamed first in the CheckUser log, those log entries are retained.
Example for illustrative purposes (user and IP data redacted and replaced with example information of what I mean):
19:14, 6 September 2021, Doug (Miraheze) got users for 1234:5678::/32 (talk | block) (Trust and Safety—Terms of Use enforcement investigation) 19:13, 6 September 2021, Doug (Miraheze) got IP addresses for ExampleUser (talk | contribs | block) (Trust and Safety—Terms of Use enforcement investigation)
Note that even if with the removepii.php, the log action for getting users for a given IP address or IP address range (top line) was always retained, and should continue to be. The issue is the getting IP addresses for a given user (bottom line).
I'd suggest fixing this so that the CU log entries for the target are renamed, then remove those log entries immediately thereafter, if that makes sense.