Google replaced “Share” button in local knowledge panels with “Save” button.
The share button was added to local knowledge panels last fall.
Here is the new knowledge panel with “save” button.
Here is what Knowledge Panel looked like from October 2016 until today:
And here is a Knowledge Panel screenshot September 2016.
The “Save” feature has been available in Google Maps app for quite some time and allows users to save listings to their lists.
The “Share” feature (which is still available in non-local knowledge panels), allows used to share listings via email or social media.