Potentially big issue for those who use the Google & YouTube Shopify app to sync products from Shopify to GMC. Because the Google Merchant API is replacing the Content API on 8/18, when you migrate the app it will change all your product IDs. That means all historical data will be gone.

There's a workaround (if you do it before August 18), and also the Google Ads Liaison has said "we're looking into this" so it's possible Google will come up with a solution.