I found the old question (which happens to be mine) with the link to the migrated post. That's how it looked 30 minutes ago:
After that I fixed a typo in a word and now it look like that:
As you can see on revisions page link remains the same, and the target post is still visible, but it seems that because the link actually refers to the original (migrated, and currently vanished) question, it's not parsed correctly to display post title instead of raw link.