Actually it depends on the way the developers/publishers work. South Park & Assassin's Creed are fine when it comes to music because Ubisoft own the copyrights to the music, even though they get 3rd party composers to make it but the composers are contracted by Ubisoft. You still have to check this though as sometimes some 3rd party composers may sign contracts where they keep the copyrights. GTA and SR on the other hand just use 3rd party music all together.
I'm assuming they used a mixed library of 3rd party music and their own or they might have placed a content ID on a specific song because they're trying to protect sales for it. If that's the case, you can contact EA via email firstname.lastname@example.org and ask them about it. EA also require you to email them for permission before you upload anything to YouTube, so if you haven't, I recommend you this ASAP.
I usually disable the sounds in my games to prevent copyrights from hitting me, you could try and edit your video and replace the sims tracks with a similar substitute that you can find on Royalty free sites