I thought that April's Fools Day was the 1st. Or at least, it looks a lot like the typical announces of that day (i.e. the one by ElevenLabs of this very year).
I don't know what to expect from that. I'm not sure if even a conversation, as we understand it, would make sense with them.
As to conversations and whether cetacean communication has a syntax, I think that's a super interesting question. I know next to nothing about cetacean communication but a quick PubMed search turned up this reference which looks like it might be a useful jumping off point for the literature in this area:
King SL, Guarino E, Donegan K, McMullen C, Jaakkola K. Evidence that bottlenose dolphins can communicate with vocal signals to solve a cooperative task. R Soc Open Sci. 2021 Mar 17;8(3):202073. doi: 10.1098/rsos.202073. PMID: 33959360; PMCID: PMC8074934.
I don't know what to expect from that. I'm not sure if even a conversation, as we understand it, would make sense with them.