Apart from TTSA I have been thinking about what the US Navy specifically might have to say about UFOs.
Context is important.
Part of the problem regardless of which branch we're talking about (or even which nation's military for that matter) is the admission that they are powerless to intervene in any way. Luis Elizondo has said as much. When this first broke in 2017 I heard him say something to the effect of locking your house every night and setting the alarm yet waking up to find muddy footprints inside. Nothing's broken or disturbed but is it a threat? Excellent way to put it. Anyone's defense services would be reluctant to admit that they can't do anything about it under any circumstances. In context I think during the Cold War it would have been anathema to make a public statement like that and probably is a major component of the of history of total denial.
Specifically with the US Navy - we correctly think of it as the most advanced and strongest naval presence in history but has been demonstrably suffering from a case of human crapulence. Personalities, money, ass covering. This is why the 7th Fleet has been running their multibillion dollar vessels into all sorts of things. Just because it's out of the news cycle doesn't mean the problem has been totally corrected. Both it and any carrier groups assigned to its area of operations have a number of daunting tasks assigned to them. First line of anti-missile defense and confronting Chinese territorial expansion are two that come to mind instantly. Their training problems reach back more than a decade, probably almost two and just like those huge carriers this isn't something you can just turn around on a dime.
Years of Warnings, Then Death and Disaster: How the Navy Failed Its Sailors
In the current climate the US Navy is in a rush to catch up to public perception; to make that sophisticated machine work as expected. Seems to have been a manpower, training and leadership problem that illustrates the humanity and human foibles underneath all the uniforms and tech. They are still struggling with maintaining the proper level of readiness in the face of the real world missions at hand.
In that context I'd think the Navy would be highly unlikely to gratuitously make anything we'd recognize as a 'disclosure' statement. One more thing to admit inadequacy to. I also think that in light of all that even if the top brass believed (or even knew for a fact) that alien craft have been whizzing around, since they haven't been really bothering anybody and nobody can do much about it that they went back to worrying about the more mundane problems at hand.