If you have a good staff, simply flipping a switch and changing the current status-quo can hurt your organization it a few different ways, so that desire to get where you want to be probably would be better achieved by a slow approach that encourages them back to the office, at least those who are amenable to this “change”. Then, for the holdouts, you have to be careful how to deal with those situations in order not to either lose your talent, or alienate those who have come back to the office and wonder why everyone isn't back.
Sounds like you have already covered this ground to me.
I have a ton of credibility with this group because the other board members remember that I was also the ONE board member who was adamantly opposed to the lockdowns and the “temporary” WFH arrangement back in 2020 — because I warned everyone that it would not be temporary.
The most likely scenario will be that the company will eventually migrate back to a full on-site operation over the course of 5-10 years … and it will be done through attrition as the holdouts move on or retire.