The "has changed" type is bound to the Last Boot and IOS alert types by design. It's going to show up in more alerts than that, but is not functional for these. I know this due to having seen the back end SQL in the Trigger Query created by these alerts when I worked at SolarWinds and out in the field deploying the alert. You can see this by creating an alert with this option then run this query on the database:
Select TriggerQuery from AlertDefinitions Where AlertName = 'Name of your alert'
Once run copy the returned value into a notepad and look at the has changed. You should see something like this:
((select count(*) from AlertValueChanges where TableName = 'Nodes' and FieldName = 'LastBoot') > 0) and (NodeID in (select NodeID from AlertValueChanges where TableName = 'Nodes' and FieldName = 'LastBoot' and (DateDiff(s, Changed, getdate()) < (60 * 1.2)))) /* Do not remove this comment HAS1101CHANGEDTBL|FLDNodes|LastBootHAS1101CHANGED */)
As you can see this points to the LastBoot field.
with a volume alert you'd see the same thing:
(Volumes.VolumeSize = Volumes.VolumeSize and ((select count(*) from AlertValueChanges where TableName = 'Nodes' and FieldName = 'LastBoot') > 0) and (NodeID in (select NodeID from AlertValueChanges where TableName = 'Nodes' and FieldName = 'LastBoot' and (DateDiff(s, Changed, getdate()) < (60 * 1.2)))) /* Do not remove this comment HAS1101CHANGEDTBL|FLDNodes|LastBootHAS1101CHANGED */) )
It's not setup to do anything outside of reboots and IOS changes.