Brother's site says my printer does support AirPrint. And through the printer's internal web server, I can see under Network -> Protocol that AirPrint is there and enabled.
I have the binary blob driver installed, so I guess this explains why two entries appear for this printer under Printer settings in Ubuntu.
So, a minor mystery is solved, and I now see that I have the option of removing this driver.
And I'm seeing lots of printers come with native PDF/DVI support which is nice.
For printing academic research papers in reverse page order to hand staple and read, indeed you don’t need drivers.
Brother's proprietary garbage driver is not needed for their older printers; there's a reverse-engineered 'brlaser' driver that you can use instead.
To be honest, I have no idea how. It just shows up as a network printer.
Ah, and also on the newwer Brother printers one has to do a complicated configuration menu dance to get rid of "Toner cartridge empty" warnings, in order to do a "Toner Reset", which lets one continue to use a half-empty cartridge. Some kind of fools' tax, it seems.