No, it's not the official divorce yet. They still have to get approval from the priest and go before a court, there's still like 15 or so more chapters before the official divorce. Just keep reading it! I swear it gets better. Also if you're impatient, there's a novel that's updated to wayyyy past the divorce chapter
https://www.lightnovelpub.com/novel/remarried-empress-17031322
Here you go. Skip to chapter 137 if you want to read from where the manwha left off. Yes, it's fan translated to English as there is no official English version yet. It's far behind the korean which is around 250 chapters long and is still updating.
So did they divorce? Im not gonna read if this isnt gonna be the divorce chapter