I know what C U Next Tuesday means in a derogatory way, but ngl if I really had a meeting scheduled for next week with the person who said it to me, I would just assume that’s what they were referring to.
Yes, in this case the meeting was on Wednesday, but my initial thought would be to wonder if I was misremembering what day the meeting was supposed to take place.
Even if you know about it, it’s not always obvious depending on the context. However, if I have a brief but unpleasant interaction with someone who I had never met before and never planned to see again, said it as I was walking away, then yeah - it would probably register that they were being a dick.