There is no true Halacha on how one wears their tallith. Even when halakhic decisors such as Maran Qaro make such statements, it is not for the intended purpose as being a binding halakha. You see this very clearly if you just read a few sentences before your quote:
Orach Chayim 8:2 -"The manner to wrap oneself goes according to the
way people wrap themselves in clothing."
These are suggestions, not halachically binding. You find other codifications making similar mentions or suggestions.
Such as Nehar Misrayim, written in the 1900s on the laws of Egyptian Jewry. i actually have pictures to verify this was how it was done. So you have instances of an entire community, post Shulchan Arukh, not following what was written. Why? Probably because they already had a custom and did not feel the need to follow a new suggestion.
Nehar Misrayim Halachoth Sithsith 4:
ד) במצרים רובא דרובא דהמוני עם משלשלין כל הארבעה ציציות לצד פניהם
והטלית מקופל על צוארם וראוי להודיעם שלפחות בשערת העטיפה. יברך ויתעטף
בו ראשו ורובו ויעמוד כן כדי הילוך ארבע אמות ואח״כ ישלשלנו על כתפו.
4) In Egypt the most common way is that one drapes all four ṣiṣioth to
their front and the tallit is folded on their neck. And it's
appropriate to inform them in their time of wrapping. He blesses and
wraps his head and most of his body in it and will stand up in the
space of four cubits and afterward will drape it over his shoulder.
Also, before Maran ruled the way he did, there were many other methods brought down for how to wear a tallith. Including all 4 sith sith in front, all 4 in back all thrown over one shoulder, and the list goes on. The Yemenites were not the only community in recent times to wear their tallith with all 4 in front. The original Ashkenazic custom was also to wear all 4 in front.
Here are some other examples of how other communities wore their sith sith. Notice that they are wearing it as an actual GARMENT, not just some extra cape they plop on when they walk into an air conditioned synagogue. The photos are a mix of Afghans and Yemenites. Thanks goes to MoriDoweedhYaa3qob for these pictures.