@HollaAtYourMomma I agree with you 100%. I actually came across a debate about build mode and if it should be considered "gameplay" in comparison to "live mode" gameplay. The thing is, I noticed a while back how the gurus would show much more recognition to builders when it came to new game content and even referred to building as "gameplay" during a live stream. From that point on, I feel as though the game has been misdirected and pushed more towards builders. I think it's one of the major reasons why live mode is getting hit with so many glitches and is lacking so much. Though build mode is an aspect of gameplay, live mode is the main source of The Sim's game (or... well, it was suppose to be) and the focus on live mode gameplay, has been extremely lost. Live mode has become saturated, repetitive, buggy in its entirety and the focus of what was once the main factor of The Sims game, has been placed on the back burner and has taken several seats. It's disappointing and discouraging all around to see one of the major aspects of the game which is suppose to be based around Simulation, take a damaging hit like this. We as players who actually PLAY the game, should be focused on a bit more than we are, instead of builders getting so much attention.
Anyway, I honestly do not think that a sim aging up will alter the tree. However, it is The Sims and we just don't know smh My suggestion to you is to, do a trial run with your family. You can call it a "test save". If you have been using the "save as" option and have previous saves, then jump into the last or previous game session that you played prior to your current save. (You shouldn't run random tests under a current save, unless it's unavoidable) Then jump into the household of the sim or sims that you want to age up. Once they age, check your tree to confirm whether or not the tree was altered upon them aging. Doing this will allow you to test it out before you age them in your most recent to current save. Now, if you have been saving over your game by simply hitting the "save" option, then jump into that most current save that you have and do the same thing and check your tree. After that, you can just quit out to the main menu so their aging up won't save, unless you want it to. Hopefully, that all makes sense.