Fan fiction at best is a grey area and at worst is blatant copyright infringement.
The community seems more than happy to leave it in that place rather than put it to the test by publishing something like that or attempting to make money from that.
As soon as someone tries to make money from it, even if just to recoup self-publishing costs there will be a lawsuit and it'll be decided concretely, probably not in the community's favor.
Yudkowsky has already made money off it by gating chapters behind receiving a certain amount in donations, which is part of why I find it really strange that he's apparently now trying to explicitly get Rowling's attention.
I didn't know that, donations are baiting the lion, I suppose it helps though that his story is almost completely separate from canon. That's a very risky path to walk though.
I offered to post pre-written chapters at a higher speed (1 per 2 days instead 1 per 4 days) if a medium-sized charity I cofounded many years earlier made its annual donation target during a matching grant. Beware that HPMOR has a hatedom, and don't believe everything you're told about it.
The Author's Notes recently:
"I decided long ago that once HPMOR was fully written and published, I would try to get in touch with J. K. Rowling to see if HPMOR could be published in book form, maybe as HJPEV and the Methods of Rationality, with all profits accruing to a UK charity. I’m not getting my hopes up, but I do have a rule telling me to try rather than automatically giving up and assuming something can’t be done. If any reader thinks they can put me in touch with J. K. Rowling, or for that matter Daniel Radcliffe, regarding this matter, I do hereby ask them to contact me at yudkowsky@gmail.com."
