This is written right  after reading Rob Bensinger's relevant post and andeslodes' comments. That discussion touched on a topic I have long held a strong belief about. I purposed first-person perspective is not physically reducible and ought to be regarded as primitive. Following that, questions such like "which future mind is me?" or "which mind ought to be regarded as myself in the future?" does not have an unequivocal logical answer. 

To demonstrate this position imagine this: You are Elon Musk instead of whoever you actually are. Here it is not suggesting that your physical body and Elon's switch places. The world is still objectively the same. But instead of experiencing it from the perspective of your current body (e.g. in my case that of Dadadarren's), now you do it from that of Elon's. The subjective experience felt and consciousness accessible is now from the Billionaire's physical point of view instead of your current case, viz. you are Elon. 

Everyone but Elon himself would say the above is a different scenario from reality. Each of us  knows which body our first-person perspective resides in. And that is clearly not the physical human being referred as Elon Musk. But the actual and imaginary scenarios are not differentiated by any physical difference of the world, as the universe is objectively identical. 

So to quote Arnold Zuboff (not verbatim), it is a question of  "Why is that you are you and I am me?" (hopefully with the above context this doesn't sound like a tautological question begging). It is something without a physical explanation. I have long held this "which person is me?" is primitively known. (The more appropriately worded question should be "which thing is me" as self identification happens prior to even the conception of personhood) It is a fiat fact so fundamentally clear to each one that doesn't have or need any explanation: the only accessible experience comes from this body, and that's me. Nothing more to it. 

In problems involving brain-copying machines, "which brain is me?" ought to be answered the same way: once the copying process is over and finding myself waking up as one of the brains, "which brain is me?" would be apparent. But short of that, without subjectively experiencing from the perspective of one of the brains, there is no way to analyze which of the two I would wake up to be (other than out right stipulations). 

This experience-based primitivity also means inter-temporal self identification only goes one way. Since there is no access to subjective experience from the future, I cannot directly identify which/who would be my future self. I can only say which person is me in the past, as I have the memory of experiencing from its perspective. 

Treating the future human being who will recognize the current me as his past self—the one whose body continuously evolved from mine— as myself in the future is something everyone seem to practice. It provides better chances of survival for said physical body, which explains why it is such a common intuition. I purposely refer to it as an intuition as it is neither a rigorously deduced logical conclusion nor a primitive identification. It is a practice so common we rarely have to justify it; a consensus. 

Devices such as mind uploading and teletransportation goes beyond the traditional intuition. Our intuition was form in an idiosyncratic circumstance, and it proved useful in such situation.  Answers to questions of future self involving those devices cannot be purely derived from our old consensus. It would invariably involves reinterpreting and/or expanding it. And that is not a strictly logical exercise but a heavily value-laden one.

The consensus is no more. One might say the traditional intuition still holds water without the same, continuously evolved physical body. So that I shall regard teletransported copy of me as my future self without a problem. Others might held that the traditional intuition doesn't depend on physical subgrade, I must regard any mind in the future who consider my current self as their past a future me.  Such that I shall regard the uploaded mind as a future self no less than my old-fashioned carbon body. But others might say the better survival chance for the physical body is what drives the original intuition, it makes no sense to disregard it: so neither does an uploaded mind or the teletransportation qualifies as myself in the future... None of that would be, logically speaking, wrong. They just diverged at the axiom level; their difference stems not from distinctions in their respective optimization logic, but which objective was set to be optimized at the very beginning. 

So we should be skeptical to claims of solving such questions by superior logic. "Which future minds ought to be regarded as myself in the future", is more a discussion of whose starting point is better than whose reasoning is. Proponent of a particular camp is, at the end of day, promoting an implied set of objectives that ought to be pursued.