No; I never played GT5, but that sounds just like retrievers from COFH. My understanding of conveyor belts is that you slap one on a pipe and it will suck items out of the thing the pipe is connected to ( just like the retrievers from COFH ). How is that different from this new thing, except for the filter aspect? Though actually iirc, the COFH retrievers could be filtered too.
If I understand it right, the retriever is like an "inverse" conveyor; instead of pushing items in the pipes it's connected to, it requests (pulls) them from the pipes it's connected to.