I occasionally get games from Latin America and the DLC issue is a real problem.
My first run-in was with The Witcher 3. Couldn't play the expansions, and I had to get a US copy. This guy had the same problem, and the CDPR people told him it was incompatible:
The other time I remember was with Horizon Zero Dawn, and the expansion The Frozen Wilds.
CUSA has two different IDs: CUSA01967 CUSA07326
With the CUSA07326 being the one specifically for Latin America.
I am well versed with the problems of games from different regions; so don't be too quick to be soothed by someone's words of false confidence. But I suppose worst case scenario, you trade it back in and purchase the US version, and also having been taught a good lesson.