Very good question. I learnt something new, i.e 'BGP' protocol :), had no clue about BGP protocol. Anyway, did some googling and checked some NetApp resources. I couldn't find any use cases for "BGP" protocol in Intercluster LIF usage. However, BGP LIFs are node specific, and so are intercluster LIFs so that's the only commonality I found.
Let me try and put some light, it may be worth raising a ticket to NetApp just to get a clear cut answer.
According to NetApp document: Failover is disabled for the BGP LIF (Automatic VIP). However, when it comes to IC LIF, mechanism is very simple and straight forward. It is a best practice to configure at least two intercluster ports per node, so that there is a port to which the intercluster LIF can fail over. This is for a reason that IC LIF cannot failover to different Node unlike 'Data' LIFs.
Considering this I believe, BGP is more suited to 'Data' protocol LIFs (Front-end). For intercluster communication , stick to standard IC LIF setup. I don't know if this makes sense but someone here will know for sure.