A number of girls I've been with have said that business has been a lot quieter for them of late. Even the established ones. Some are considering leaving.
The country's economy is in the pits, so it would be reasonable to infer that the escorting industry is as much affected by this as is any other industry at present. So I think the OP's inference is right - i.e there are less girls advertising because there are less girls around.
It all bodes badly for escorts and punters alike. Difficult days ahead on all fronts.
"Don't be reckless with other people’s hearts. Don't put up with people who are reckless with yours"