The Hajj is the fifth pillar in Islam. It is an annual Islamic pilgrimage to Mecca, Saudi Arabia, which is the holiest city for Muslims.
Saudi Arabia has already put a ban on Muslims travelling from various countries, particularly those are affected by coronavirus.
There are likely to be comparatively fewer people attending the Hajj compared to the last year.
One reason could be that the other countries would have their own provisions to contain the coronavirus outbreak rather than Saudi Arabia measures to restrict people from attending the ritual.
This is a very significant event and must be dealt with care and measures. Around 1.8 million Muslims from nearly 160 countries attended the Hajj pilgrimage in 2019. It would be difficult to monitor so many people in one city when the stay can be from 5 days to 30 days.
Back in 2009, during the swine flu outbreak, the Saudi most senior religious leader (Grand Mufti) rejected the calls to suspend the main Hajj pilgrimage and called it absolutely unjustified. At that time he said that it was permissible for pilgrims to wear protective face masks during the Hajj.
So, in that context, I do not think the Hajj would be cancelled and of course, it cannot be postponed.
The Hajj was cancelled many times in the past for various reasons such as disease, conflict, the activities of bandits and raiders etc.
Last week, the Saudi King Abdulaziz Foundation for Research and Archives (https://www.darah.org.sa/index.php/st-and-rep/darah-events) released a statement noting 40 times in history during which the Hajj was either cancelled or the number of pilgrims was extremely low.
Some occasions when Hajj was cancelled