If we didn't "change our brain into an animal one" we wouldn't be animals at all, lol. We wouldn't be able to function.
And sure, instincts can be controlled. if you're a human or tamed by humans. But there won't be any more humans, or any willing to "train" you, will there? Even the smallest things, like cats scratching their claws against trees are instincts. What's the point of being an anthro if you're still expected to act like a human?
All I'm saying is that you can't ignore the facts. If I'm not going to question it, the people who develop the technology certainly will anyway.