Class PhabricatorPolicyAwareQuery, on line 220:

if ($need) {
  $this->rawResultLimit = min($need - $count, 1024);
} else {
  $this->rawResultLimit = 0;
}

When querying for events for user availability, rawResultLimit is 0, resulting in unexpected results. This task is a placeholder to figure out if this is a problem, if the current workaround in PhabricatorCalendarEventQuery around line 177 is okay, or if there is a better fix.