When you put in a made to spec order to a supplier when something is being developed, in most cases, it comes with the following caveats... First 3-4 months seed stock, estimated annual usage contracted in as a monthly deliver quantity "guarantee", with some obvious supply chain limitations built into the contract agreement.
My guess is, they never expected the MIL variant to be so successful when MOA is bought by many more users for most scopes of all brands. So their initial seed stock and monthly forecasting will not be able to keep up with demand for this specific variant of the product. T
They have likely (hopefully) since updated their demand, but production depends on manufacturer supplied parts lead times as well... Which in most cases are ordered and delivered to the final assembly manufacturer in the same seed/forecasting blocks as mentioned above.
So even if they've increased their forecasting moving forward for MIL variants it could still be quite some time, or never, for when production will increase to meet the demand and keep some inventory in stock for shipping.