I'm inclined to agree with this. I'm guessing someone who didn't really understand different share classes recommended them. They didn't bother to carefully think through what rights that new class would have. Instead (as many do) they just thought by giving them a different letter means you can pick and choose whatever you want whenever you want in terms of their rights.
The liquidator is now in the awkward position, of seeing there being different share classes, without clear written rules on what their entitlements are. The liquidator won't care or want to get involved in the debate, but equally they don't want further down the line either shareholder to try to lodge a claim against the liquidator if that shareholder thinks they should have got more. Hence they just want you to confirm, in writing for their records, what you believe the situation to be. They'll then follow that.