@sarah that makes total sense, because those tests should not be too hard to develop/maintain, and you can easily put them in CI.
But I don't think they can replace contract testing, since they require merge/deploy, so I would consider them a "safety net", not a part of the vital "development feedback loop" that normal CI gives you.
Later, you can start deploying ephemeral environments from branches and run the smoke tests there, but that kind of stuff has a medium-to-high maintenance cost...