Short answer: yes. Your data stays yours, always.
Your articles never leave your ownership — they live in your Notion workspace, and Emovart only syncs copies of the pages you've shared in order to render your public site quickly. Each help center uses its own read-scoped OAuth token, so we can read the pages you connected but can never edit or delete anything in Notion.
All traffic between your visitors, Emovart, and Notion is encrypted over HTTPS. And if you ever delete a help center, its synced copies are deleted along with it — your Notion workspace is left exactly as it was.