Quick note for anyone who has this issue.
You can avoid this by uncomment the following lines
writers.stream.filters.priority.priority = 4
writers.stream.filters.priority.operator = "<="
writers.stream.filters.type.name = KalturaLogFilterType
in "/opt/kaltura/app/configurations/logger.ini". This will avoid the DEBUG logs in the "kaltura_api_v3.log".
Also double check that you have the kaltura_api logrotate file linked in "/etc/logrotate.d/".
lrwxrwxrwx. 1 root root 53 May 17 12:50 kaltura_api -> /opt/kaltura/app/configurations/logrotate/kaltura_api
That was it for me.