Dwajasthambam or flag pole is an important aspect of Hindu temple. So, is there any link between Kurukshetra war in the Mahabharata and the Dwajasthambam in Hindu temples?
No, there is no link connecting Kurukshetra war and Dwajasthambam in Hindu temples.
People assume this connection because the Bhagavad Gita was narrated by Bhagavan Sri Krishna to Arjuna in the Mahabharata.
Dwajasthambam give information about the deity worshipped in the temple. When a flag is raised on the Dwajasthambam it indicates temple festival or auspicious occasion.