Was willing. In his younger days. Seems to have gotten over the compulsion as of late. Past actions no guarantee of future behaviour. Etc.
Anything is possible, but we must ask what is more likely given the motivation and justification we've seen in the past. Presumption is on the side of Spock acting to save future lives. Spock's behavior in the new film is part of that which is at issue (i.e., does this make sense?) so we cannot simply point to what Spock does in the movie. Past action is no guarantee, but it does form the presumptive basis of character.
And it's not about playing God. It's about knowing a little bit more than your peers and being able to act on that knowledge to save lives. I don't see why Spock or anyone else wouldn't. It's not a TPD violation. There are no obvious "defeaters" in the cases I have discussed, aside the bare possibility of butter fly wing disadvantages. He has positive knowledge of how to prevent the countless deaths using mundane means which would not upset the balance of power or deprive the Federation of its many other problems and challenges (e.g., the Klingons).
I've already noted that they could hang a lantern on this as on opportunity (i.e., this is a perfect justification for them not to have to retell every TOS story - not only is this a different timeline, but Old Spock can steer them away from old problems so that they may have new adventures).
Ah well, it's no big deal, but I do think it is an interesting question. As of now, there is a big question mark hanging out with the surviving Vulcan elders.