Suburban areas are not urban areas, so we really have 3 distinctions, Urban, Suburban and Rural.
I live in a suburban area and not because of proximity to the office, I’d be really surprised if large numbers of people currently living as I do upped sticks to a rural backwater because they can work from home 4 days a week, also there won’t be many rural backwaters left if it did happen.
There is a significant cohort of ‘office’ workers whose office is in a manufacturing facility and whose presence is required ad-hoc, carrying out functions such as engineering/scientific expertise and supervision. Working remotely is not new, most companies of any significant size use remote/outsourced services already, like HR screening job applicants or payroll.
Junior roles and graduates: How can you expand rapidly with lots of new junior/grad hires and train them, supervise them? You need a location where company values, culture and work practices are instilled. Manufacturing facilities adjacent to urban areas often have a young workforce who want to live in rented accommodation in an urban area.
After we’ve finished subsetting all of the above, I don’t see a mass colonisation of the hinterlands, it will be driven by lifestyle e.g. someone who until March was commuting from Mullingar to Dublin has now demonstrated they can work effectively from home, but remember that person could now be located in Poland or Vietnam.