No, but it is the 'Rathbone Cup', which in Cornwall teams take seriously! You still seem to be missing the point, that if a player is too old (no matter how much), they are not eligible to play.
I've been involved with a Youth Football Club for several years and sadly there were similar situations with teams pulling out of both league and cup competitions, when our teams progressed through to U16s and U18s. Only on one occasion were we unable to field a full team for an U18s league match, so we played the game with ten players. Would this not have been an alternative, or you could have considered registering one or two 16 year olds beforehand, as back-up, as these are eligibile to play for U18s, and the fixture could have been fulfilled in a sporting manner, rather than your team being disqualified!
to be honest with hindsight, this would have been the better option, but with players pulling out at the last minutem unfortunately we were left in the uncomfortable postion of 10 players and no keeper or 11 players... we chose the 11 players
as it so happened we dominated the game and probs didnt need the 11th player, but i guess whats done is done