Just tried it out on my instance, the schema gets included in the mail but there is no button:
^ Google’s markup tester
Oh god, I should have read the documentation more. You have to register with google so the button shows up at all.
Some points come up which seem really bad to me:
Consistent history of sending a high volume of mail from your domain (order of hundred emails a day minimum to Gmail) for a few weeks at least.
We are currently only approving Go-To actions for very specific high-value usecase with high interaction rate (e.g. Flight Check-in, Shipment tracking links).
Maybe “Read full topic” is too unprecise for this recquirement:
Label of button needs to reflect clear action to be taken and must be true to page the user is going to