I havn't played the game since Aug 14th 2016. I loaded back in last night before the NEXT update and I still had that save. I've rebuilt my PC since then as well so no hard copy saves where made on my end. Getting back into this game is a whole new experience. Since I only played during the first week of the initial launch.
Yeah they're not updates, they're community events that are changed weekly. Shouldn't (in theory) effect trainer