First prove that there is an age gap to close. Until anyone can do that, no one should be promoting it in any way.
So if it is not possible to prove either way, then in your opinion no one should be promoting or encouraging to close the age gap — even if anecdotal evidence strongly suggests that the age gap is a large cause for a disparity in girls having available shidduchim.
Therefore, in your opinion, even if the age gap is causing women to be unable to get married, it should not be addressed or fixed despite the anecdotal evidence that is happening, because it cannot be proven.