“If what they have is a 100% totipotent cell, what they have is a Day 1 embryo”
A fertilized egg is considered totipotent, meaning that its potential is total; it gives rise to all the different types of cells in the body. You are right in your understanding of the word totipotent, but there is no way to obtain totally totipotent cells without an embryo.
The cells that are being created here must be pluripotent, meaning they can create any kind of cell in the body, except those that create a fetus. An egg is still necessary to create an embryo or a fetus, and God help us if that ever changes.
I think they're on the verge of doing just that. Have you been keeping up with the UK's Human Fertilisation and Embryology Authority (I was going to say Orwellian-sounding, but no, I guess it's Huxleyan)? They are doing really freaky things with laboratory-based human reproduction. I think the idea now is to develop an "entity" which is just abnormal enough that it wouldn't be considered quite technically human. For experimental purposes.
Not that it matters. They don't seem to grasp the ethical objections to manipulating nascent humans. And the legal "barriers" are made of cobwebs. Thee are no meaningful limits at all.