At our levels of cricket, have seen people with the carbon backed Kook bats, the odd laminate and a few other long-time banned bats.
Some Umpires struggle to see to the other end of the wicket so the last thing on their mind is what is supposed to be legal and not.
As people have said, the new laws are aimed at
David Warner Pro players who use 50mm edges. Only kidding - Warner isn't the only Pro player who uses large bats. I can't see the point in it myself - most batmakers will tell you that the benefits are marginal. The main gain for power is pressing!
I wonder if they will try and Police how a bat should be pressed next?