If you wish to continue to assume that Data's head being present in the past is not contingent on him time-traveling in the first place, feel free to continue assuming.
As seen in
Time's Arrow, Data's head was present in the past
before he ever time-traveled there. Thus, it seems to be the assumption of TNG that Data's head being present in the past is not contingent on him time-traveling in the first place, because after the head was found Data would have been free to choose not to go back in time at all ( there are other things in TNG canon which demonstrate this point ). The illogicality of predestination paradoxes aside, from the perspective of STXI it is not correct to say that Data never went back in time. From STXI's perspective Data's time travel has
already occurred. It is an event from Nero's past and Spock Prime's past. Even if writer intent is discarded and STXI is treated as an exercise in single-timeline theory, it represents a prior alteration to the timeline. It does not matter if the Abramsverse is "the" timeline or a branching timeline created by Nero's time travel. In either case Data's head is there when the Abramsverse comes to be. When Nero and Spock leave the Prime timeline in 2387, they leave a timeline which at that point included Data's head being there between 1893 and 2368 in its past. Nero appears in 2233 of the Prime timeline's past, right in the middle of the period when the head was there.
Captain M said:
I don't think Nero and Prime Spock's presence in the Nu-Trek verse altered anything other than what we saw in ST09.
A more accurate way to say that would be to say that the Abramsverse is only different from the Prime because of the changes wrought by the presence of Nero ( and Spock ). That goes beyond just what we saw in the film because of the so-called "butterfly effect" and the unseen consequences of the things that we did see. However it is said, that idea is the whole point. Data's head doesn't disappear from SF just because Nero went back in time. Of course, it is always possible that for some unknown reason the consequences of Nero include someone discovering the head much earlier than the TNG timeframe, possibly even before 2258, and taking it somewhere, destroying it, whatever, but that is beside the point. That's why I've been specifically stating that the head is there in 2233, meaning at the creation of the Abramsverse.
Captain M said:
With the Nu-Trek verse, I'm inclined to imagine its a universe where things happened differently, not negatively like the MU, but differently.
It is quite obvious that things happened differently from STXI alone. But this does not start happening until Nero's arrival. Before Nero's arrival, the Prime universe and the Abramsverse have the same past.
Captain M said:
For example, lets say that the Eugenics Wars never occured, Arik Soong would find something else to do, perhaps working as an inventor for the Federation (explaining some of the more advanced technology).
I would support the idea of a Eugenics Wars retcon of some kind, in order to bring them into consistency with actual history as it stands now. However, STXI does not provide for the Eugenics Wars happening differently or never occurring in the Abramsverse, given that the Eugenics Wars supposedly took place in the past of the Prime timeline prior to 2233. There are no differences in the past of the Prime timeline and the past of the Abramsverse prior to 2233 ( excepting possible alterations of the past occurring in the future of the Abramsverse ), because the Abramsverse is created by Nero leaving Prime 2387 and appearing in Prime 2233.