Actually I think WFH would improve this. If both the west and east coast colleagues have to commute to their respective offices, there is a lot of wasted time during the beginning & end of the day. A person may arrive at the office on the east coast just as the west coast is waking up. If both locations were simply WFH, there would be more useful overlapping daylight hours to use because neither side has to commute. Additionally, one office could have modified hours such that they more overlapped with the other office either as a standard or simply as needed.
Main problem is a blurring between work life. With one office no one would dare schedule meetings too early or too late in the day. With different time zones you might have to have a 7am meeting on the west coast or 7pm on east coast. There needs to be strict calendar blocking to maintain sanity.
