It's definitely an alternate history map, and I hope it's an accurate potential map of an uncolonized North America if it's cultures grew to nation state sizes.

I'm European so I'm not meaning to offend, but there's something very interesting to me try to visualise how America could have grown without colonisation, and perhaps this is through my European lense but I'd imagine borders would move and groups would swallow eachother up. The scale of countries on this map is pretty comparable to what we see in Europe and Asia, but I don't know enough about America to know if this is respectful to the placement and potential of Native American groups (e.g I think I've read before the the Comanche are a successful seperation from the Shoshone that was largely due to their expansion due to horses, which would have happened very differently sans colonisation), and I'm not even sure if this map follows natural borders like mountains and rivers, largely because I'm just not that familiar with America.

This one seems most accurate: https://native-land.ca/

OP's map relies a lot more on Western notions of nations and land ownership than you would have found for many indigenous tribes.