There is evidence US generals said differently. That was the case during the Soviet-era, as military officers had no problems saying the Soviets may have parity or even ahead in some areas. Bringing it to current events, a US Air Force general was recently quoted on Chinese missiles "out sticking" US missiles. There's also general agreement among US experts China is a near-peer in the space domain.
Oh I find that very debatable; especially in this case when we're talking about a specific type of weapon system whose obvious roles are meant to directly confront each other in event of hostilities. There is much more ego and pride mixed into a nation's fighter aircraft than almost any other weapons system that a military fields.
No nation and no high ranking military officer would be willing to openly concede parity or superiority of an opposing force's fighter aircraft vs their own top line aircraft, and if it were close they would end up rationalizing out statements like training, offboard force multipliers, or differences quality to try and "even things" for any sort of public comment.
To be honest I'm even a little bit offended that the article was even posted here and we're discussing it in a non-ironic way. I thought we were all better than this, and the base psychology that drives these sort of statements is something we've all seen many times, many years ago repeatedly.