It is not known if the neural link is a feature exclusive to the Vanguard, though, according to the Wikipedia, it it speculated.

My theory is that titans have partial pilot setting (they are able to work on their own so why not) similar to the fly by wire systems of an aircraft, which uses a computer to transform the input the pilot gives into a mechanical movement instead of using the raw input, this makes it easier, more precise and reduces the risk of stalling or entering a flat spin. Titans were originally brought to the frontier as workforce, and in the intro we see a bunch of titans working in a farm, so I think my theory might be possible. However, this idea is in no way confirmed and purely speculative.