As always, Slack is committed to protecting user and company data. Giphy doesn’t receive any information about users or even companies using the Giphy for Slack integration, and only sees Slack usage of the Giphy API in aggregate.
— Read on daringfireball.net/linked/2020/05/15/slack-giphy
John Gruber’s post about the Giphy acquisition inspired a response from Slack. This is good; Slack is where I use Giphy the most.