Why do you think you don't need four pilots for flights over 12? Current FARs are designed around the idea that no pilot should be in the seat over 8hrs. Last I checked, if you go over 12, you need four pilots to make that work. Is the FAA and/or congress pushing for this change anytime in the foreseeable future? If so, that's news to me. Is there new fatigue science that would support a reduction of crewmembers on long haul flights? Again, news to me if there is.

Is there technology in the works that may (key word) allow for a crew reduction at some point in the future? Surely. But that tech will require big changes in infrastructure and aircraft design, which will drive big costs for operators. It will need to undergo extensive testing. Most of the countries in the world will have to agree on implementation (Europe ain't flying a reduced crew into JFK without approval from US authorities). Pilot unions will have to buy off on the idea (good luck with that). Public concerns will need to be addressed. Finally, individual pilots will have to make an assessment each day, much like they already do under part 117, as to whether they are fit to operate in what will undoubtedly be a higher stress and workload environment.

In short, there are a LOT of hurdles for this idea to overcome. Not saying it can't or won't happen eventually, but judging by the speed at which major changes tend to happen in aviation, I wouldn't be too worried unless maybe I was in high school & considering the career.