Let's get back on topic, shall we?
I believe another Colossus would be built, assuming the GTVA has managed to withstand the financial/political impact. Capella had a relatively high population, meaning a large number of displaced persons. After a massive Shivan attack and the loss of the system, there would definitely be squabbling over the GTVA's ability to fend off the Shivans, and about what to do in case of another attack. If the GTVA could quell fears and maintain control, then it's not far-fetched to believe that they would construct a second Colossus, as another symbol of Terran-Vasudan co-operation, and also to protect the populace.