Not wearing a kippah/Yarmulke stems from modernization, even by Sefardim. This “minhag” is probably only about 100 years old when many came to the US. Although as others have stated, the term MO is not traditionally used by Sefardim, modernity has definitely crept in.
One way – and I’ll probably get a beating here for saying it – you can determine if a community or group is truly ״modern” (applies to all Jews, and I’m specifically not using the term MO) is by observing what percentage of their children stay Frum. If it’s only in the range of 50%, there’s no sugar-coating it.