In the stock transmitter, the final amplifier plate voltage is 1800 volts, so the 2000 volts shouldn't cause too much of a problem. The modulator originally ran only 1200 volts on the plates of a pair of 811A's, and the modulation transformer was just barely step-down, with a turns ratio of something like 1.15:1. Even so, the modulator would just barely make about 85% modulation in most transmitters, if you were lucky.
Running 2 kv on both with a common power supply should give better modulation, but the final tank cap might arc over on modulation peaks. This is assuming that the G-C driver stage is capable of fully driving the modulator at the increased plate voltage. With a common power supply, the modulation transformer should have turns ratio of about 1.4 or 1.5 to 1. The 572B's MIGHT work OK with the stock audio driver and mod transformer.
Don k4kyv
