Sure maybe the "experience" hasn't changed from a UI standpoint but FB is weakening WhatsApp's end to end encryption and mining your conversations so under the hood the experience is radically different.
There is a reason the founders of WhatsApp quit FB post acquisition (literally leaving hundreds of millions of dollars behind) in disgust over the privacy abuses Facebook was proposing. https://www.cnbc.com/2018/09/26/whatsapp-co-founder-explains...