While you can update your listing, guests with pending or confirmed bookings won’t see any updates or changes you’ve made to your listing.
Guests search for and booking listings that meet their specific needs. Therefore, as a host, it is important that you ensure your listing is represented accurately at the time when it is booked.
If an amenity that your upcoming guest was expecting is changed, let your guest know immediately. If they no longer wish to keep the booking, you'll be responsible for cancelling it so your guest can re-book elsewhere.