I suspect the partial in-office/wfh arrangement will be fairly rare. Office space is costly to use only 2 days a week. Companies can do hoteling but it breaks down when you have very technical employees who like very particular desk setups (multiple monitors, chair positions, special keyboards/mice). The more common arrangement will probably be mostly WFH but meet up occsionally in some per-hour rented office for collaboration. Sucks for WeWork to have blown itself up before this :).