As of June 2019, The Sims 4 will no longer support 32-bit operating systems according to the development team. However, players with older systems will still be able to play thanks to a Legacy Edition that will come out the same month.
“We regularly evaluate our technologies, and to continue growing, improving, and optimizing the game, we have made the decision to retire 32-bit support.” was the word that came from community managers on the EA Answers website.
As for players who cannot update to a newer 64-bit system, EA will be releasing a Legacy Edition later that same month. That edition will not receive any updates or bug fixes, however will include all content that is available up to the 26th of February. If players want to experience the newer stuff packs, they will have to update.
Players will be able to save progress by transferring over game saves. Online features are also set to be axed on the Legacy Edition.