SKB says:
"Trigger release latches can be retrofitted with TSA accepted key locking latches".
As far as Delta's requirements, you would need to speak to Delta about that:
https://www.delta.com/content/www/en_US/traveling-with-us/baggage/before-your-trip/special-items.html
SKB can be reached at 800.654.5992.
Mark H.