https://www.miamiherald.com/news/local/immigration/article312042943.html
Around 800 detainees showed no record on ICE’s online database. More than 450 listed no location and only instructed the user to “Call ICE for details” — a vague notation that attorneys said could mean that a detainee is still being processed, in the middle of a transfer between two sites or about to be deported.
If you keep records, people can be found.
If you deport people to their correct country like Cubans to Cuba, then they might be able to access resources. If you send a Cuban to Mexico then they are a fish out of water. They will start sending Venezuelans and Mexicans to an African country so that they're less likely to show up in there original country get taken advantage of and possibly be enslaved.