The majority who answer questions on the forums are users of the software ourselves. We generally don't know what Adobe is working on or when they might be adding content. Is there a particular other reason why you're switching to Fresco? Do your airbrushes work in Photoshop on the iPad? I would suggest going onto the Fresco Userpage and adding a feature request so that others can help you vote the idea of more Photoshop Brushes being added to Fresco.
I know there's a few brushes that don't work in Fresco. There's a dry brush I love in Photoshop that doesn't work in Fresco. If its not working, it might work in the future, since this app is constantly improving