Where do you think this policy ranks among other Hybrid policies, such as weekly:
1. 1 day in office and 4 remote 2. 2 days in office and 3 remote, etc
If you're looking at whether you can attract people outside the HQ city, I think the two factors are frequency and length of in-office time. More than a few days is tough for many to be away from home, and more than a couple trips a month starts to be a lot of travel. I say this as someone who has regularly flown to a different city for work.
If you're just talking about attracting people who are a 90 minute drive away vs 45 min (for example), 1 or 2 days per week in office each week might be easier to swing.
Maybe if the company specializes in furnished vacation rentals and always has inventory...