I agree on the name, yeah, and I was also surprised by Opa. My assumption in infrastructure-code cases like that (not sure if actually true with Opa) is that they want to leave the door open to a dual-licensing solution, so if Opa ends up being a killer technology, the AGPL poison-pills it enough for commercial customers that they'll be able to sell paid licenses.

Not sure what a cleaner alternative would be in that case. Perhaps just state that explicitly? "You can use the free version of Opa to build open-source webapps [define appropriately], but need a commercial license if your app is not open-source."