The latest information I got today regarding the "corona exceptions" in Hilton Athens:

"Kindly be informed that Executive Lounge is currently closed and for now food and beverage offerings are not provided in other venues. However we are in the process of finalizing which offerings will be re-implemented and we can advise you via email as soon as this information is released. In regards to breakfast please note that currently it is served in Oasis Pool Bar & Restaurant in individual boxes and it is provided on complimentary basis for Executive floor room bookings.

Regarding the pool please note that due to new Health & Safety regulations only the outdoor pool is operating."