3 possible scenarios here.
1. Crewe knew hours before they let Oxford United know. They then turned up at the ground, putting their own players at further risk, and all our players, the match officials, as well as all those involved with the operational running of a club on match day. If this is true, then it is a very serious allegation and could possibly lead to criminal charges for intentionally endangering others. If this was leaked a number of hours before Crewe arrived then I would have hoped you would have advised the club as such to minimise risk to all involved?
2. Oxford United were aware, but for some reason decided not to make this information public. By these actions, they have put their own staff and the match officials, press etc at risk as well as incurring huge costs in preparing for a game that would never take place, and also having to pay for a deep clean of changing rooms etc. If true this would be incredibly reckless by all involved.
3. You made a sweeping comment about the season not completing and entirely by coincidence our game is called off. With absolutely no pre-knowledge, cryptic or otherwise, you post in a way that implies that you knew all along. If this is correct, and I suspect it is, then I would urge you to consider the implications of what you say.
My guess is that Crewe found out that the player was ill, dropped him and hoped that would have been enough. It was incredibly naive and reckless, but I'm not sure it was done with any malice. And I certainly don't think there was any conspiracy going on.