I think, if you don't change the name of an art board, it should automatically count up if you copy it.
I'm working a lot with small art boards, that i copy over and over to create versions. So if i just drag it over with strg pressed, I want it to count up, so I know my progression through the process.
And if you don't want it, you can just change the first Artboards name and it won't count up.
I think that would be a really easy and nice addition.