What is the maximum number of users that can join to collaborate on the new whiteboard ?

Hi @kentan 

At the same time 100.

Best regards,

See this section in this document @kentan 

Is there a maximum number of users that can access a whiteboard at the same  time?

Zoom Whiteboard supports up to 1000 editors in standard conditions, however our service does have safeguards for low QoS conditions to ensure at a minimum the host and up to 30 other users can continue to edit.

https://explore.zoom.us/media/whiteboard-security-and-privacy-faq.pdf