Sweden has started doing medical age tests on migrants who claim to be minors. The tests are still voluntary and the results are not binding in any way. The first results are in with the 'expected' results: 76% of those claiming to be minors are in fact over the age of 18. they tested 581 asylum seekers (96% were men, 4% women). 442 of them (430 men, 12 women) were over 18 according to the test results. 5 of them (all women) were possibly over the age of 18. 134 of them (133 men, 1 woman) were possibly under the age of 18. None of them were certainly under the age of 18.
So, yes, those who expected the majority to lie about their age have been proven correct.
Don't be so sure they aren't. They have every incentive in the world to lie. They already violated international law once by seeking refugee status in Sweden instead of first peaceful port.
Either way, even if they are just 16, it does not change the fact that two years later, the vast majority of adult refugees are male.