Im having two OSX devices and network setup using AirPort Extreme connected to printer with USB. From both of these OSX devices Im able to print wireless and everything works fine for these. However I also have iOS device and from what I understand I can print only using AirPrint in case of iOS. In this guide they say AirPrint printers connected to the USB port of the Apple AirPort Base Station or Time Capsules are not supported with AirPrint. So it means I should disconnect usb printer from the AirPort and connect to wireless network directly, but in that case I would be unable to print from my OSX devices? (I assume this AirPrint functionality is not available in OSX, but Im not sure) Does this technically mean that you can use Airport Extreme to connect with printer centrally shared for the network but cannot use it for iOS and OSX devices at the same time??
Connect your printer to your network instead of the USB port. Your Mac can print wirelessly if in the printers network both via the AirPrint driver as well as the printers native driver (might need to be downloaded from the manufacturers site). The native driver might give you more options (if you have more than 1 paper tray or other non-default features).
Your iOS device will print via AirPrint or alternatively there might be an app from the manufacturer that allows printing via the app but not on a system level.
You can use AirPrint printers on macOS. To do this you must plug it in via USB to the wifi router, then on your mac, use System Preferences to add the printer by clicking the little + button. Use the network tool that should find it via Bonjour (a feature built into most devices). This should work for both Mac and PC, as well as iOS.