As a non-gamedev person but just gamer, I should expect that this will replace TAA anytime soon? Should it replace TAA?

Basically no... Analytic AA is a really hard problem for video games, and I know of no general purpose solutions.

For font and 2D vector rendering it's likely, in fact afaik, some solutions, such as Slug already do.

But for 3d rendering I don't know of any solutions.

For an intuition, consider two triangles that intersect the same pixel.

Consider if say one has 20% coverage and the other 30%, does that pixel have 50% coverage, 30% by one, 20% by one and 10% by another, or any other conceivable mix? It's very difficult to say without selecting specific points and sampling directly.

I tried to do this for polygons rendered aliased by computing edge position and reweighting pixel colours. It looks great when polygons are large but it breaks for small polygons (when polygon size is close to pixel size)