This is an obvious first move as Google moves Websites from a minimal viable product to something more full featured but still easy to use. The inclusion of Posts creates allows a business to add additional relevant content over time, a win for the business and Google.
Simultaneously they announced the ability to add up to 9 photos distinct from your GMB photos and a quicker time to publish. It would appear that means that the rendering of the final HTML is not done until you visit the site the first time.
Since introduction Google has sustained a build rate of over 5000 new sites per day and they currently have 1.25 million sites created. While many of these are in the developing world, a significant percentage are showing up in the US and Europe. The inclusion of Posts should cement that trend.
The product is still missing basic SEO features like Title Tags but for a business that has chosen to only have a Facebook page this product could offer significant impact and value.Google Updates GMB Websites to Include Posts as They Pass 1.25 Million Sites Created by Mike Blumenthal