Why couldn't it be?
The question you cite has a long list of characteristics of a McDojo, only one of which is abnormally fast progression. At that, neither "Brazilian Jiu Jitsu" nor even "Gracie Jiu Jitsu" (due to a legal suit within the family) are trademarked terms, so I could run a "BJJ" school with whatever testing requirements I want. In actuality, I'd probably be barred from their tournaments, but why would that bother me? After all, external tournament fees are going to external people.
A potential example
Just to add another data point, Gracie University Online has been accused on being a BJJ McDojo. Initially, they allowed online certification of a BJJ black belt and then changed their policy to only allow you to get an online blue belt. Last I heard, the belt they send you is a "technical" blue belt and that it's not real until you visit them in person. And there are people who have received said belts online and are teaching under the auspices of their online belt.
Ramsey Dewey has a video with his thoughts on the matter which basically comes down to that it's a good thing to get the training out there, especially for people who don't have access to a school in their area, but that he dislikes the idea of a "technical" belt because he feels that belts either mean something or they don't, and that he feels you can't evaluate someone online, so this one doesn't mean anything (it's worth mentioning a caveat that Dewey isn't a huge fan of belts in general, as he feels people put too much stock on them compared to actual skill levels).
Just for fun
Example of what a BJJ McDojo might look like