I see. I'll send this conversation to our product team - they should be aware of it.
At the moment, we suggest that customers use the Data Generator feature. However, if you get used to DataGen, you can continue using it. As far as I understand, it won't be removed from the tool.
According to the latest update from Product Management, the DataGen test step will stay deprecated that means that it won't evolve but it won't be removed from the product.
We'll correct the documentation to avoid the confusion.
Thanks @NBorovykh, thats good to get the confirmation.