I don't usually do this because 90% of the time HN comments are facepalm-worthy, but since raiguard is commenting there, I'll copy and paste some relevant excerpts as further info:

[lucb1e] Is this about the upcoming expansion or the base game? I am not reading FFF to avoid spoilers and instead get the full wow effect the first time I play the 2.0 // Edit: expansion I guess, since the last 3 releases don't mention statistics (https://forums.factorio.com/viewforum.php?f=3)

[raiguard] Everything I talked about here will apply to Factorio 2.0 as a whole, whether or not you have the expansion DLC.

[keplerboy] Using fork to save the game state in the background is really clever. love it.

[bno1] I wonder how they deal with multi-threading. Forking a multi-threaded process is very error-prone (e.g. allocator locks can remain orphaned).

[atq2119] They mention that there's a rare freeze bug. That does sound like it's most likely one of those orphaned lock problems or similar.

[raiguard] The post was already getting long so I didn't mention this, but I already found an fixed a potential deadlock due to each process not closing the redundant ends of the pipe, which was specifically touted as being a potential cause for freezing. However, someone reported the bug again after that change went out, so there's still SOMETHING else causing it to hang that I haven't tracked down yet.

[milliams] When they say they removing their Allegro dependency "eliminated 123,024 lines of code from the game" I assume this is because they'd vendored in the code?

[raiguard] Yes, we vendor and statically link as much as possible to avoid dependency hell across distros and platforms.

[lupusreal] If they drop X11 support that will finally be the end of my cracktorio addiction.

[raiguard] Apparently I didn't word that section very well, because many people took away this impression. My apologies.
Factorio will continue to support X11 for as long as SDL does, in other words, essentially forever. The only change here is that X11 is no longer required for the game to launch at all. SDL will load whichever video driver is available at runtime, or if you have both, you can choose which one to use in the graphics settings.