Do you think YC told AirBnB "We won't accept you on our programme if you take investment from Paige", or do you reckon it was AirBnB's decision to join the YC programme instead of taking your investment?
(a) Based on your story, Airbnb got accepted into YC early (or at least received a strong enough signal that they would be accepted). I don't think that's inconsistent with Airbnb or YC's account, I'd just never heard about it before (amidst a ton of lore about Airbnb's early days at YC).
(b) Airbnb had the foresight to see that YC's deal was better than yours. This would actually have been non-obvious in 2008: Dropbox was only a year old, Stripe didn't exist yet, and YC's best-known successes at the time would have been Heroku and Reddit. Not to mention the fact that you were offering them 10x the cash at 10x the valuation.
So it is "weird" in the way that history is kind of weird. I don't doubt your version of events though, and I appreciate you sharing it.
And that goes back to one of the lessons from my post. I realized that for founders and investors to take me seriously and not lose deals I had to prove myself, build a positive brand by helping founders and getting smarter about this new world I was operating in.