R1:c1bd1d1b9a6a

Fix 2 minor issues with Durable Column

Summary: I left in an opacity change by mistake, and fix language on threads.

Test Plan: review in sandbox

Reviewers: epriestley, btrahan

Reviewed By: btrahan

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D12054