There is absolutely zero evidence to support this statement, especially if we are talking about a quarter full, outdoor stadium, where people are spaced apart. Pure superstition.
With regard to your statement that this sad state of affairs "can't go on forever", well, I wish that were true, but the current restrictions no longer constitute a reasonable response to any actual public health threat, and they probably never did. The population has been driven to hysteria by massive disinformation and flat-out scare tactics from the media. Things will not be returning to normal any time soon...