I has an appointment at the main Goyard location last Friday and indeed, they were out of all Artois MM bags. The SA said they haven't been getting much new stock lately. I was very disappointed to walk away without a bag and they were out of stock of the two back ups I had in mind.
But... undeterred and with some spare time on my hands, I walked over to the other Goyard location at Galeries Lafayette. They had the black Artois MM in stock and a few other colors but I didn't ask which ones since I was too excited to find what I was looking for. The SA said that they had a few left and didn't mention any stock issues.
Hope this helps! I love the MM and the size is perfect for what I'm looking to use it for, a casual travel / work tote. For reference, I'm 5'2.