Earlier quoted context omitted.
I can't provide a counterexample to the specific 3br luxury->SRO scenario, but it certainly does happen on occasion that previously expensive units wind up getting subdivided into cheaper units. I knew someone who lived in a low-end furnished room (with shared bathroom) that had previously been part of a larger unit.
I'm not sure that is an equivalent example. The previous example was housing falling into a lower tier of the market through lack of maintenance. Your example is actively retrofitting a place to be in a different tier of the market. That isn't really the same thing because your example requires new investments and is actively creating new housing at the bottom of the market rather than just allowing a place to deteri…
I used to live in San Luis Obispo, CA. There's a house in the middle of town that clearly used to be an enormous beautiful mansion. It looks like it belongs on a plantation. It's still beautiful, but it's now 9 funky apartments.
Street view: https://www.google.com/maps/@35.2749914,-120.6611941,3a,75y,...