Star Trek is a reboot yes but its also a prequel.a 2009 movie set in the 1950's on a TOS timescale.
When I first saw Spock and Uhura ,"gettin it on", my only thought was wth .
1.It was good movie watching taken on its own , but Ive seen all the original episodes a number of times and however you look at it there was never a strong connection between the two.
Even if Uhura did enjoy him pulling on his lyre in the rec room.
The pre part to that she describes him as having "satan's eyes,and the devil's ears", not exactly a rememberance of "young love"
Most of the time she found spock's vulcanism as amusing as anyone else.
Other terms of endearment
Spock:"I can think of no one else more competent to handle it Miss Uhura"
The situation you will have to look up for yourself
but you would need a very active imagination to ascribe anything remotely near a previous love interest between Spock and Uhura from watching TOS .
Her love interest aside from the unshown in southern states "kirk kiss" did extend openly to hunky black males who appeared in episodes (which was probaly all that was allowed).
2.The movie she has the "hots" for him and its reciprocated and its the only "love story" in the film.
It may not have been a huge plot element, but its now "out there"and will have to be resolved..not happily.
Everything else,mostly, aside from some time paradoxes can be explained away/"suspension of belief" will work.
3. I dont mention the original ST I-VI movies because they are sequels to TOS and nothing in them adds anything to a young Spock/ Uhura relationship.Except possibly the "Genesis effect",(see below)
3.In the ST franchise , there havent been many/any long term/intense (boy/girl)relationships between regular cast members .
ST TNG had one.
4. The actor who plays the young Spock came out as "fully gay" in 2011. So what?..perhaps,Sulu/George Takei "married some guy in the 2000's", but for an audience paying/watching something and hoping to be entertained,all the close up shots of young spock n young uhura rotated to look more horizontal mambo are kinda wasted .
5.The way its played up to now,and the "cant be dismissed" affection between Spock and Uhura in the first reboot movie,I cant see soln's aside from
a.Another Genesis effect type Spock or Uhura rebirth..mind blank.
b."Lets do the time warp again",some time paradox that will erase/remove the memories of both of the "love thang".
c.The "pong far " and blood boiling may be introduced as a love wiping device?
d."I have been and allways shall nr..perhaps some platonic undertones introduced .. groan
Either way I cant see how the Spock/Uhura relationship can be continued.
Openly gay actor in a long term heterosexual franchise relationship just wouldbt wrk for me ,,sorry. if that sounds homophobic