I'm also having this issue, and this feed leads me to believe it may be something to do with shopify.
I have all of the information needed in my footer, and I do not understand what could be low quality about my landing page. I also have every ingredient of my products listed with what they do, along with all nutritional panels, so the excuse about it not being transparent isn't correct.
Google has shut down my merchant account AND suspended my ads account as of this morning. I don't know what to do.