Question:
I removed one of my fb pages from the import social media page, but added it back afterward. However, the chatbot flows won't appear anymore, but upon testing the flow in messenger is still working.
Answer:
Deleting a Facebook page would also delete resources and automations related to that page, like chatbot flows, autocomments and others. If the flows are still working in messenger, these are probably just server cache/memory. This cache memory will be removed as well the moment you create a new flow using the same Facebook page.
Please be reminded, as well, that flows created on two separate Facebook accounts are different even if the page is the same.