First instinct is to delete the previous one; given how Bluesky timelines work, two posts with the same text next to each other just look like dupes. Quote post could also work to show that they're linked together. Or maybe most simply just adding a "UPDATE:" at the beginning of the post.

Obviously the tricky part is correlating the posts. Not sure if you track anything like that in your system, but given the text of the two posts is the same, you could probably just check the bot account's posts for a previous post with the same text.