The circus knows that Dick became Robin and then Nightwing.
Listen they know that kid! They know how he operates. They were worried at first but before they left they talked to Dick and Dick was absolutely ecstatic so they decided to keep their mouths shut.
Like they let him fly on the trapeze, they probably wouldn’t have blinked at him being a vigilante.
They make stops at Bludhaven now to say hi and read up on his pursuits.
They always knew he was meant for the center stage.