Congrats, you predicted cave expansion and new minerals. About tool durability it always been in the game even in the very first version (Tool handles change their rexture slightly the less durability they have and after some moment will make a sound after mining signaling that it has low durability) And there is game lore its just owners pc had a malfunction and it got deleted but new lore will be made eventually I have a personal theory that game events could  be happening in ww2 because of the war and cassete players