Not totally correct, yes the implication is there, but US has tax agreements with many countries such that your tax burden will not be affected significantly compared to a local resident at X country that is not the USA or it's territories.

Tax implications only really affect you at high income levels (think millions of USD/annually). The cases where you are considered 'double taxed' are, IMHO, rare, and in fact mostly do not happen. This comes from a person who detests taxes of all kinds.

There are guides out there including by the US government detailing how expatriates can manage their taxes, suggest reading on them.