Would make sense in that context. Big homecoming headline show. Pull something special out the bag.
I assume it didn't go well if that was the only time.
As Rick mentioned and I've posted here before, an old Queen collecting friend, Marc Tretman, from California, said that they played a bit of Fairy Feller's as an improv at a gig he was at.
Probably Santa Monica in either 1975 or 1976. He said some guy was constantly yelling for the song and to appease him, Freddie started playing a bit of it on the piano (can't recall if the others joined in). Marc is a reputable and very knowledgeable Queen fan who supplied me with many of my very first rare Queen videos, back in the late 80's. I met him in Hollywood in 1992 and I can attest to his good character, so I'm pretty sure the info he supplied was true.