What will happen? Will YC yank funding over this? I hope not -- that would set a dangerous precedent and make me, for one, that much less willing to pursue YC funding.
If the founders didn't want the OP before -- they especially aren't going to want him now that all this has occurred and threats about getting YC involved etc.
The bottom line -- you can be terminated for any reason, even if it's the color of your shirt on that particular day. Does that make it "right"? Well, that's a perspective thing.