Possibly the opposite. If you own a home on a lot that previously you could only build one or two units on, but now you can build N+ units, that lot is worth a lot more.
The math of this: a lot with 1 unit, worth $1m today, becomes a lot worth $3m and 10 units on it. So the cost per unit is $300k; unit price goes down, but value for the original land owner goes up.
yea but once anything starts getting actually built prices have to fall, that's sort of the point, and it's not like demand is so high that every house in the Bay Area would need to be replaced by an apartment building.