I just had something similar happen to a review that I left.
Last weekend I had my best Airbnb stay to date and left a glowing (and long-ish review). I re-read it just prior to submitting, felt it was good and accurate, and hit submit.
The review that posted was cut to: "I can't say enough about what a great host Kate is, and what a perfect place this is for a large family (we are family of 6, with four young kids). From first"
The original first sentence that said "If I could give this stay 10 stars I would." was gone. As was the rest of the review, describing an exceptional host, house and location.
Any reason that Airbnb would edit a glowing review? I'd like to write to Airbnb to find out why the original was edited, but can't find a way to do this.