Not particularly. You can still do all the fancy and not-so-fancy tricks regarding packet routing. As long as each router knows a "closer" router to the destination, you're fine. This is identical to the current setup in that regard.
As a matter of fact, it would probably be easier to make dynamic. (Router A gets a packet for router Z - router A wants to send it to router B, but router B is currently congested, and router A knows that router C is an alternate route, so it sends it to router C instead.)
Now, there are circumstances where this approach is not particularly valid. In particular, on wireless networks. However, TCP over wireless networks isn't exactly great either. (TCP and this approach both make the same assumption: namely that most packet loss is congestion as opposed to actual packet loss.) This approach is for the segment of the network that's wired routers with little to no packet loss disregarding packets being dropped due to no cache space. I.e. this approach is for the reliable segment of modern networks - wireless should probably have an entirely different underlying protocol.
Router A knows that router B is congested - but this is actually due to congestion in the link between router K and router L. How does it know which of router C or D would be using the same link? It has to have a global understanding of all the routing paths, no?
Routing the packet to Z and telling you that the path to Z is congested are mirror images of each other; it makes sense to use the same mechanism for both.
As a matter of fact, it would probably be easier to make dynamic. (Router A gets a packet for router Z - router A wants to send it to router B, but router B is currently congested, and router A knows that router C is an alternate route, so it sends it to router C instead.)
Now, there are circumstances where this approach is not particularly valid. In particular, on wireless networks. However, TCP over wireless networks isn't exactly great either. (TCP and this approach both make the same assumption: namely that most packet loss is congestion as opposed to actual packet loss.) This approach is for the segment of the network that's wired routers with little to no packet loss disregarding packets being dropped due to no cache space. I.e. this approach is for the reliable segment of modern networks - wireless should probably have an entirely different underlying protocol.