I’d advocate for the later flight “just because stuff happens”. In that case they’d be carted to the Admirals Club or Flagship Lounge because of class of service eligibility if they’re in Business until it’s time to board the flight.

As well, “Priority boarding and re-accommodation status” in case they’re scheduled on the earlier flight and miss it.

The original plan with hotel overnight might still be the best, given change and FSS fees, etc.