I agree with your analysis that remote working won’t be something that is sustained, but I disagree with your ideas about why this is. The cost of providing remote equipment (and even paying for Internet access) is a fraction of the cost of paying for office space. So there’s no fiscal reason to have people being cube slaves. Secondly, the 90+ minute commute drains energy and is a complete waste of everyone’s time, so “interpersonal interactions” are a risible excuse for creating billions of tons of CO2 and wasting endless years of people’s productive lives. Any company that relies on serendipitous interactions is a company that deserves to go out of business.
No, the real reason we’ll see everyone back in their little cubes is simply because managers have little or no clue how to assess productivity; seeing people in their pigeon-holes is all that most managers can rely on. And for the sad people for whom the office is their social life, let’s be honest: they ought to be paying more attention to their personal needs, not pathetically substituting transactional relationships for something more meaningful.