Yes, a catalog gives pretty much the same result (and is prettier since you can immediately see the OP), but this would allow the feature to be found on the top of the page.
Also, combining it with /all/ (ordered by board) allows for people who only lurk one board to still be able to see every board.
Also, because of how MLPchan works, one could simply mouse over a thread in this listing and see the OP, allowing someone to actually browse the first page of every board relatively quickly.
However, a catalog feature otherwise should still be added. Because it would be awesome.