Can funds from a LN channel be recovered if both participants suffer data loss? Is there a way to recover funds if both channel partners suffer loss of the latest channel state? Would both having their static-channel-backups be sufficient to recover the channel?
I don't know exactly how static channel backups are implemented in lnd and what is being saved there but I can give you some general thoughts and at least a partial answer. 

If A and B both lost their channel state but still have their master key / mnemonic seed they can probably derive the key that was used in the 2-2 multisig wallet that is used to encode the payment channel. 

Generally if two parties agree on how to spend the funding tx of that multisig wallet (e.g. 50/50 or in a different ratio as someone might have a screenshot of the channel state and both parties consent) they can do so.