I think it
is true.
It is right to say that the UK is unusual in
automatically validating other countries' licenses, but actually most countries have a similar process albeit involving some paperwork. Outside JAA, it appears this is even more common especially if the one you are trying to validate is the de facto world standard (FAA). This is an area which is hard to research because these facilities (especially where a whole new local-country license results i.e. a
conversion) are rarely advertised openly. I've been offered one such direct conversion for my FAA CPL/IR to the local CPL/IR (and there must be more) involving no more than paperwork but had to have a "relationship" with a local commercial operator).
BTW this thread is duplicated
here but with some additional input.