I see what you’re getting at. It is all the same Saint Expeditus, worldwide.
There is only one such saint. The veneration of him occurs in many European countries and then spread to many countries in the New World including the Caribbean islands, South America and New Orleans.
Saint Expeditus - the same saint, worldwide - was purged from the calendar for the same reasons as Sts. Philomena and Christopher, namely there was insufficient evidence of them in the eyes of the Vatican, which was also anxious to reduce the number of saints on the calendar. Certain saints became favorites of the practitioners of various forms of hoodoo and were associated by these practitioners with folkloric pagan gods or demons.
It’s not that there’s a “different St. Expeditus” in New Orleans, it’s that there is a hoodoo/ voodoo cult of him that has its own practices that do not comport to the teaching of the Church.
It’s fine to pray, in the sincerely Catholic manner, to St. Expeditus, or to other saints who are still on the calendar but are favorites of hoodoo practitioners such as St. Jude, St. Anthony of Padua, etc. I have prayed in this manner to St. Expeditus for his intercession (I simply say the old collect for him that was said at Mass for centuries on his feast day when he was still on the calendar). And of course everyone prays in the Catholic manner to St. Jude and St. Anthony.
It’s wrong to believe in the “hoodoo” version of such saints or practice the prayer rituals associated with them. You are likely to get a demon on the line rather than the saint.