On Notebook, you can edit posts in 3 places: When creating a new post by hitting the Post button, when editing it inline in the Feed view and when you are on an individual post view.
The link preview wasn't working on the individual post view and I was constantly asking Bolt to make improvements to the 'Edit mode' - and testing it out on the individual post. And while Bolt was saying it was fixed, it did not seem to reflect it in the edit mode on the individual post.
Latest I decided to test it out on the inline edit and realized it was working there. So I went back to the chat and said 'Make link preview updates to the edit mode on the individual blog post' page.
And voila! it worked.