From Replace links with the current question title in comments on MSE:
No, because comments are processed on the fly. This means a page with 12 links would incur 12 additional database queries -- every time the page is loaded.
Comments are meant to be lightweight. If you want this, put your links in a post, where it is already supported.
Links are stored in the database as just the text. Not the markdown and html (like posts are). When a link is rendered, it grabs the text and renders it right then and there. To have links get auto nice titles, it would either mean:
- Doubling the storage requirements of comments (there are 38,091,590 undeleted comments on Stack Overflow alone)
- Suffering a performance hit when you render a page for each comment that has a link to another post.
- Scan the raw link to see if its a link to another post
- If so, hit the database to find the post (if its undeleted) and substitute the name
Neither of these appear to be acceptable tradeoffs for the ability to auto-pretty link a post for SE's developers and so, well, if you want a nice name to a title of a post, then you're left with the traditional format of
One can also always grab the SE Comment Link Helper.