Content pack sharing

Let us first clarify Sharing vs Content Pack.

1. When you share, the users will get an email notification. The user has to click the link in the email to activate it. Without clicking the email, if they go to PBI.com directly they won't see the Shared dashboard. To receive email, you don't need full O365 account. You just need a valid business email account.

2. When you publish content pack, users will see it under Get Data -> My Organization. There is no emailing in this scenario. When the content pack author deletes the content pack, it goes away from all the users.

https://support.powerbi.com/knowledgebase/articles/651631

If a group member has not customized the original content pack, then the content is automatically removed, and the dashboard and reports associated with that content pack will no longer be available (and won't appear in the Navigation Pane).

If a group member has customized the content pack, the next time she opens the customized dashboard all tiles from the original content pack will be gone.  But tiles pinned from other reports will still render. The original content pack reports and dataset will no longer be available (and won't appear in her Navigation pane).