Will the Ohare modernization project have ohare overtake atlanta once more as the busiest airport ever?

Yes and o'hare is now on the top of the rank

O'hare is already the busiest for flights in and out, because it has so many freight carriers flights.
It could possibly take over Atlanta for passenger throughput, if the major airlines ( like American ) schedule more connections there. United is already the king of connections at O'hare.