It need not have ever had it, even to be effective for fighting, if it was assumed most students would have some basics, already. This is similar to the argument that Ueshiba may not have taught all he thought was truly necessary for Aikido, because his early students all had significant experience in some basic areas (notably, probably strikes and close-body throws). He focused on teaching what they didn't have. If it was common for the folks coming to WC to have some basic grappling (and, almost automatically, some basic counters to grappling), it may not have been necessary to include that in the art.I'm sure Kung Fu has takedown defense, or more likely did at one point and was forgotten, discarded, etc. over time by most practitioner and/or teachers. If it was truly developed to fight, and people have been taking each other down since the dawn of fighting, it most likely existed somewhere.
It's not like takedowns are a thing that were just invented within the last decade or three. There might be more modern ways to take people down and more modern approaches, but I'd highly doubt it's never been practiced formally in Kung Fu circles up until the anti-grappling guys thought they knew what they were doing.
I'm not a Kung Fu guy, nor am I a fan at heart; I'm just playing the overwhelming odds here.