The Help Center article about the privilege to flag posts still refers to the old situation where 6 flags were needed:
What happens when I flag something as spam or rude/abusive?
The spam and rude/abusive flags are designed to automatically eliminate truly disruptive posts through the collaboration of the community.
- 6 flags – the post is locked, deleted, and the owner loses 100 reputation.
However, as documented in the FAQ What are the ��spam” and “rude or abusive” (offensive) flags, and how do they work?, this is now 4 flags instead of 6. This may have been intended as a temporary measure, but it's been in effect for 6-8 months now, so the privilege page can be temporarily adjusted as well. Perhaps it can even be dynamically populated based on a site setting - this accommodates the situation we had in the past where several sites (The Workplace, English Language & Usage) posts only needed 3 flags.