Cosmos in the Lostbelt Story Ending

Just finished the FGO Cosmos in the Lostbelt storyline. It was an amazing ride and a good ending even though...I'm still doubtful that this is really the end of it. As it stands right now the ending is basically a full reset that basically makes our entire journey "never existed in the first place" with both Mash, Fujimura and Olga Marie living their life normally like if they never met. It's not like I don't like the idea, but it feels like a cheap way out instead of trying to justify the absurd things that happened over the years.

Hints lead me to think that they are preparing something big that will happen on the 31st of December and I can only imagine it'll lead to the fabled "part 3" even though who knows what it'll be all about.
Lots of speculations around the Foreigner chapter and other ideas, but well...only a few more days and we'll know!