It isn't so much as a reply on a re-tweet, if you comment or "reply" to any tweet then the layout is the same as any other social media site and nests it under the post. Whereas for re-tweeting it is more like sharing something, like a link or an article, and your desired message into a post, just like here in lemmy your title or message is at the top and your content is under it. In this context the tweet is your content.
You could always chronic urticaria like me, and just spontaneously breakout for no aparent reason, but at least over the counter antihistamines keep it at bay, it's hell if I forget to take it though.
My assumption would be they have 48hrs to book a service that takes time to fix and provide notice of scheduling.