I make of them the same thing I make in retrospect of US senator reactions to receiving classified briefings about WMDs in Irak: they could be complete fabrications, meant to deceive senators as much as the public.
Furthermore, even if it is absolutely true that the military has a huge host of UAP that they have worked hard to identify and failed, and they are briefing the senators on the details, that does not mean that there is no explanation, it just means that trying to accurately explain a phenomenon that happened once or twice is extremely hard.
I have a backlog of dozens of bugs in my product that a customer has seen once or twice, with logs that show me they are right, that make no sense given the code and that we have been unable to reproduce. Should I conclude that alien devices interfered with my software to deceive my customer? Obviously not: complex systems are complex and have many corner case behaviors that we may never have a completely satisfying explanation for.