D&D 5E Commander's Strike and Haste action

[S'mon]

While Haste does require one weapon attack with the Attack action it grants (meaning you technically can't grapple, shove, or- disappointingly- Radiant Sun Bolt with it), you can still forgo that attack to Commander's Strike.

That's my interpretation.

You're spending your Haste Attack Action & your Bonus Action to grant the Cs, hardly unbalanced. You could equally use one of your attacks from your regular Attack Action to get the same result anyway so it only occasionally makes a difference - you used your regular Action to do something not allowed as a Haste action but also want to CS.