Geodesignhub is a open workflow for geo-project management. What this means is that your existing data, tools and models will work seamlessly with Geodesignhub as long as they follow OGC standards and formats.
Geodesignhub already natively supports the GeoJSON format via our extensive API. GeoJSON is commonly used in most internet based software. However accessing this GeoJSON requires basic programming knowledge. Some of our customers need to download data for use in GIS software e.g. in QGIS. Previously, we had supported downloads in Shapefile format but this has now been dropped in favor of the Geopackage format. The download button now reflects this, other than that there is no real change for you.
There are a number of advantages to switching to Geopackage, you can review the Switch from Shapefile website to go into the technical details.
We are really committed to providing a modern digital geodesign experience, we also recently dropped Shapefile support for our maps converter. I plan to write more about the converter some other time.