The Saudis will take a huge hit in the pocket book as the Haj is a major money maker for the kingdom.
You are right — plus oil prices are down AND Neom is a flop AND they are losing materiel in Yemen
But more importantly, this is a major hit to the Wahabbi and probably the wider Muslim pysche - it is one of the 5 pillars of Islam that muslims MUST visit Mecca at least once in their lives. If the Saudi regime bans this, then that should set Muslims enraged.