Bear in mind my awareness of my own limitations in this regard, but consider some variation of:

Code references are no longer treated specially, but now, just as any other scalar, when they appear on the left hand side of ~~, because their previously special treatment broke the commutativity of the operator.

Ie. That special treatment meant that coderef ~~ X did not produce the same result as X ~~ coderef

IMNSHO, it would have been better to have applied the special treatment of coderefs, to both sides of the operator, rather than discard it completely. The whole point of a coderef is the result it produces, not its (transient) value.