So apparently the delete button to delete your own posts is unavailable. I don't ever remember being able to delete your own threads but I do remember being able to delete posts.
@bwfcwalshy Ah. Just poking around for a little bit it seems that there's no straight forwards way to do it
Hmm... Turns out you can edit posts now and the delete button for threads is nowhere in sight (for me at least. I couldn't find it).