I don't know much about the US housing dynamics but it seems very unlikely that prices will get lower due to less parking being required. It's more likely the builders will profit more.

We went through a similar situation with airplane tickets where I live. The govt agency in charge of aviation and the airlines all wanted the free luggage requirement gone citing cost reductions. They got it, the fares didn't get any cheaper and now you have to pay extra.

I really don't see the 17% reduction in space required for parking being passed onto buyers. People will continue to demand 1-2 parking spots because that's a high cost area and people buying there don't care that much about that discount, if that even happens.