Unless the value returned from your Named Query changes you should not expect your table to update.
Also, you can replace
if self.getSibling("Checkbox").props.selected == True:
with
if self.getSibling("Checkbox").props.selected:
When I executed your script as part of a transform while in preview mode I see no change occurring when I click the checkbox because the data returned from the Named Query has not changed. If I change the state of the checkbox, exit preview mode, and examine the binding, it re-evaluates and then shows the changes.
Design mode, with checkbox unselected:
Preview mode, checkbox has become selected:
Design mode, after the binding has been examined (which triggers a re-evaluation) and OK has been clicked:
In my local environment, the third row has no matching values between my datasets, while the other three rows do have matching values.