What if a person or company committed a significant investment to such a project, contingent on a crowdfunding push hitting certain thresholds?

A pilot is sort of that, actually.

TV pilots are produced as one-offs (often independently financed) and then shopped around to networks as a way to obtain funding for a full season.

So it's a small step from that to saying "We'll finance this show if you can produce a pilot on your own."

pretty sure that's what's happening here.

warner bros is covering the distribution and marketing.