Logan53015 If this is about transferring between console and PC/Mac, my guess would be never. The fact that content doesn't transfer is by design and is probably a financial decision as much as anything else: EA has to share console-related profits with the console manufacturers but can keep all the profits from PC/Mac sales to itself. EA probably wouldn't want to miss out on the PC-related profits, nor would it want to pay Sony or Microsoft to allow PC users to play the same content on their consoles.
There are a couple of master threads (info and feedback) about transferring packs here, if you're interested in continuing the conversation:
[FAQ] Why don't my expansion packs transfer between platforms? | EA Forums - 8607336
Cross-Platform DLC Transfers for The Sims 4 | EA Forums - 11857073
Since this thread is over a year old and has been answered, I'll lock it here.