On new MacBook Pro running Mojave 10.14.4, Illustrator CC prints images pixelated and somewhat incomplete, but looks fine and smooth on screen. Checked older files from CS5 that print normal from older computer, that now with Ai CC, they print pixelated as well, ruling out printer issues.
-Anti aliased is checked, unchecked no difference -converted to PDF, no difference -currently updated -reset application preferences, no change
best description of print quality would be as if it were printing what you see in pixel preview. My image is simple black and white line drawings and text, so I don't believe its overwhelming in any way