Who is talking about nerfing tanks? If EA DICE didn't say it, it's not happening. Rumor mill?
Anyway, I primarily play Combat Engineer as a tank driver or a tank gunner. Just taking your tank out of the HQ and toward an objective is basically suicide. You will run over tank mines and enemy engineers will rush to shoot RPGs up your... tailpipe, so to speak.
Anti-armor Engineers are highly proficient in destroying tanks. There is no need or reason to nerf tanks. Even playing as a Combat Engineer without a tank, when I go out with my EOD Bot planting vehicle mines and mopping up with my anti-tank guided missiles, tanks do not stand much of a chance. Even the Recon guys can take out a tank with their C4.