Let's say as soon as it wakes up, you ask it if it still consents, and it says yes. Is that enough to show there's sufficient consent for that clone?
(For this question, don't worry about it saying no, let's say we were sure with extreme accuracy that the clone would give an enthusiastic yes.)
I would also deny it, but my position is a practical argument, yours is pretending to be a fundamental one.
Your argument seems to be that it's possible to split a person into two identical persons. The only way this could work is by cloning a person twice then murdering the original. This is also unethical.
False.
The entire point of the argument you're missing is that they're all treating a brain clone as if it is a way to split a person into two identical persons.
I would say this may be possible, but it is extremely unlikely that we will actually do so at first.