hi @Anonymous, the way I see this is literally an evolution, and that's how I describe in my post: http://oliverrodrigues365.com/2022/05/24/power-pages-power-apps-portals-is-now-power-pages/
If you already have a Portals, there is nothing to worry, Power Pages is a natural evolution and there is nothing to be concerned in terms of compatibility or anything, under the hood they are the same product.
The idea behind Power Pages is to add more focus and attention to the product, instead of being part of the Power Apps, this is now one level above, being its own product within the Power Platform.
Only potential migration that I see here, is about the domain, but this is not yet clear as to how Microsoft will approach it.