The wider context makes a bit more sense imo

A regulator-supervisor should not be a market participant,” said Ignazio Angeloni, a professor at the European University Institute in Florence. "It would be like if a referee was also a player … the digital euro would break this rule."

If too successful, the digital euro project could give people a risk-free place to hold their money, policymakers worry— undermining the commercial deposits that enable banks to lend to the economy.

Makes sense to me as a worry. It would be disruptive, though I'd hope it would be disruptive in a good way.