MessagePreview on native and web don't need this, but web/modals/threads/subchannels/subchannel.react.js and web/modals/threads/sidebars/sidebar.react.js sort of do since the result of useMessagePreview gets passed to a React.useMemo. Not clear if those particular React.useMemos are very useful, but this is still good practice in case eg. other places call this in the future.

Flow