If you have used Alexa or Siri, you know those can't even understand English all that well, so you are right to be skeptical they understand cat. But MeowTalk has help. You tell it what you want to believe your cat is saying.
It's like going to a psychic and latching onto any random thing they say - "I feel someone whose name starts with a J in the room" "WOW. I had an uncle named John!" - as affirmation that it is working.
In chemical and food epidemiology and other fields that rely too heavily on surveys it is this:
Their formula is literally you training the app to tell you your cat is saying what you want it to say. If a cat could speak they'd tell you they didn't create SARS-CoV-2 but they would have if they could have.
Link where I saw it in early 2020.
This important article notes that 90% Of All Meowing Comes From Owners Trying To Get Cats To Meow Back and those people are the perfect demographic for this app.