I don't think the person you're replying to is talking about office rents. Residential rents are still high, so clearly people still want to live in NYC, regardless of whether or not they're working in an office or work from home.
The number of people who want to live in cities seems to be pretty similar now to what it was before the pandemic. I don't think urbanism is dying, or, if it is, it's not because of remote work.
I would like to revisit this in 3-5 years, without an office there is less motivation to live in a very expensive city like NYC. As leases expire and companies close even more offices, we'll see where all this goes.
The number of people who want to live in cities seems to be pretty similar now to what it was before the pandemic. I don't think urbanism is dying, or, if it is, it's not because of remote work.