The developer who announced this works for Nginx the company, so I would assume (emphasis on the assume!) that Nginx Inc. was paid to undertake this.
I don't think this is a problem given that the patch is being openly pushed into the "public" source immediately. It'd also be extremely challenging to pay "the community" for a patch like this (how do you divvy up the funds? per SLOC?), although technically you could always directly pay a single contributor or two.
Directly engaging Nginx Inc seems to be both the surest way to get something delivered and avoid a lot of PR risk, if you ask me.
Normally if a company wants to take that route, they would hire one of the developers as an employee, and the employee's job would be to work on that open source project.
