The only one of those that is an example is Nigeria. All the others are just listed as examples of countries that have not conducted a census in an extremely long time. While that's a good reason to think the numbers are probably inaccurate, it's not a good reason to think they are fake.

> there's obvious fakery in the number of significant digits. If the numbers are approximations to the nearest ten million (or worse), it's a form of scientific fraud to provide a number like "94.9 million"

The numbers aren't approximations to the nearest ten million. Just because they're inaccurate doesn't mean they're imprecise. For comparison if my bank statement is missing a large transaction it may be off the true value by hundreds of dollars, but that doesn't mean they didn't count the cents for the transactions they're aware of.