Brother is no longer allowing 3rd party ink and toner too so do your research there as well.
Or buy a printer that uses refillable ink, such as Epson Ecotank. No cartridges - no DRM.
Yes and no.
Allowed? Probably no 1st party vendor allows/wants it.
Can do? Yeah sure.
Will I get warranty for violating some kind of EULA (or some other equivalent) for using 3rd Party? Probably not.
As an IT helpdesk we usually just tell them to get 1st party as the toner is not that expensive for that volume and just eat it. At least they have warranty for the 11k of printed papers.
I’ve seen reviews saying that a firmware update stopped 3rd party ink/toner from working. Both myself and my mom have Brother printers that we love and have used for years. It’s disappointing and they’re great printers but I don’t want to pay a premium on toner/ink just because. But yeah, as @cerberus_cat said, refillable ink is good too if you need an ink jet printer but I don’t know why anyone would want ink over laser.