Update: I received my 5dimes withdrawal
9/27 12:16PM: I received an email from Coinbase stating that I received coins from an external account, which may take up to 3 network confirmations before being available.
9/27 12:17PM: I received an email from 5dimes confirming the withdrawal with a Trace ID
9/27 1:30PM: All withdrawal funds cleared and available in my Coinbase account
Definitely not the smoothest transaction, but glad they lived up to their word.