If you meant adding capacity to existing roads (by adding lanes) it certainly can drop congestion as well. Expanding roads blindly CAN also make congestion worse but that's a possible outcome not a guarantee.

The point of the original "paradox" is that if you want the least amount of road congestion by private vehicles the best investment is to grow public transport but many places dump more money into roads and lower the percentage of users using public transport because "roads are where the congestion is". Hence the paradox, increasing road spending increases road congestion (in places with existing public transport).

The point of the second paradox is there exist ways to add more paths to a network that result in less flow than the network had before regardless of other conditions like public transport being available. The paradox is NOT that adding additional capacity to a network ALWAYS or NORMALLY results in less flow. In fact most of the time it does help flow (marginally) it's just a poor investment compared to the same amount spent on public transport.