I think it will be difficult to find supporting data that mandates all employees across every team are required to be in office 3 days a week. Given the related news about downtown areas where the offices are facing issues with lack of consumer foot traffic and increased issues with crime and social issues, it’s seems more likely at this time the decision is being made because of pressure from local governments.
https://www.reddit.com/r/Seattle/comments/118ihq1/seattle_ma...
https://seattletransitblog.com/2023/02/25/cities-cant-rely-o...
https://www.cbsnews.com/sanfrancisco/news/san-francisco-mayo...
https://www.latimes.com/california/story/2023-08-27/nordstro...
Additionally managers have typically been empowered to evaluate the effectiveness of their teams and their performance, but now an external metric is being forced on them without much visibility into the metrics themselves (e.g. badge in counts for their reports, how WFH while sick but not taking a sick day affects the metric, or various other circumstances). In my experience and prior to the pandemic, whether you were in the office or not was up to whatever discussions you’ve had with your manager, and it some cases there were employees that were allowed to work from home (or other states) based on the needs for that team.
So to me this isn’t returning back to how things used to be, it’s setting a new mandate that drastically impacts an agreement and expectations between the organization that hired the employee and the employee themselves without any data supporting the decision or consideration for what a team actually needs.