It's not really about ballistics, twist or throat to them, it's about contractual obligations.
If you want to manufacture anything, you have to estimate demand and order at least a year in advance from your suppliers. A barrel maker won't gear up to deliver several thousand barrels to your door without iron-clad contracts in place. There may be an option for changes, but the added cost for that will be specified in the contract as well.
So a major issue at play is that LAW likely already bought and committed to buying and ordered barrels in the various twists they originally thought the market would want based on what other manufacturers are currently offering.
If they change specs mid-stream what would they do with all the unwanted barrels?
