@The_Ratticator If I remember correctly in my last New Game I had my Sim travel to a different location-- a library to jump-start some of her skills-- before the neighbors showed up. When she returned home a few hours later there was no welcome party. I'll have to test this again to make sure it was not a glitch. I know this is not exactly what you are looking for but it might work, i.e. no welcome party and no negative relationship hit with the neighbors.
Welcome Wagon still occurs even if you leave the lot as it will happen the next day instead or when your within your home during the time it is suppose to start, which tends to be the case in more recent updates. The welcome wagon happening depends on the traits you have for said lot such as peace and quiet or if you have neighbours. Personally I hate this event as I see it as a waste of time due to it forcing you to remain home and speak to other random sims who you are not really going to interact with all that often, heck I had one happen a week later within the summer. Its better to cancel it and use mc command centre or the Ui cheat extension to remove the negative effects of cancelling said event.
Community ManagerThis is an old thread, I will lock it now but feel free to create a new topic, thanks.
