How can I force an update on the thumbnail and doc title? Slack doesn't seem to do periodic re-checks since the first time it cached the info. I've tried the command "refresh" the file, but does not work. This is in Team Drive, btw.
Got it! I tried this from RayB, and it helped: https://webapps.stackexchange.com/a/140932
- went to my test channel
- posted the Google Doc link
- chose "delete file from Slack" from its menu
- reposted the link
- Voilà! it posted with the new title and thumbnail