Microsoft has announced the availability of Custom visuals for Power BI within the Office Store. Office Store is the place where you can find apps (known as add-ins) for your Office 365 software.
With this change, Power BI is now a product in the Office store, listing all Power BI custom visuals. You can also search and filter by categories for easy navigation in case you need to.
There are already many visuals listed in the store, and Microsoft is working to move the rest of the visuals within a few weeks. The Office store will be the place to find custom visuals and use them, as well as the place for developers to submit and manage their custom visuals in the store.
It is worth noting that all custom visuals that were ever downloaded from the gallery will continue to work as usual even after the gallery will be deprecated, however newer submissions by developers will only go to the Office store.
You can read the full announcement on this page