By doing so, it implies that Whatsapp is recording, tracking and analyzing every message that is sent on the platform. It detects when a message is going viral, and it blocks your freedom to share it.
It can now be done to limit the spread of fake news, but it also means that they have the power to do such things. They can limit a message to organize a protest for example. We can now know for sure (if we didn’t know before) that Whatsapp is tracking every message you send.
It could just mean they’re putting TTLs on messages now but only viral messages reach that limit.
Not that I’m saying WhatsApp is the good guy by any stretch of the imagination. I’m just not convinced yet they’re reading the messages for analyzing them remotely.