I guess it would depend on the income level change that accompanies gentrification.
If incomes move from "low" to "middle", I don't think you'd see much of a change in laundromat density. In places like SF and NYC, if you don't have a W/D in your home, a "middle" income isn't going to give you enough cash to get one (most of the time it's a space constraint).
If incomes move from "low" to "high", then yes I could see an effect since if you have enough money, you can do the sometime-needed major renovations to add a laundry room to your home.
If incomes move from "low" to "middle", I don't think you'd see much of a change in laundromat density. In places like SF and NYC, if you don't have a W/D in your home, a "middle" income isn't going to give you enough cash to get one (most of the time it's a space constraint).
If incomes move from "low" to "high", then yes I could see an effect since if you have enough money, you can do the sometime-needed major renovations to add a laundry room to your home.