Fair point; I always forget that. IIRC, it's the first couple of arrivals of the day -- maybe the Australian flights? -- that arrive at TBIT. OP lists HND, though, which has a midday arrival time and will be at T7 barring some kind of operational meltdown.

Even if someone were to arrive at TBIT, they still wouldn't need to schlep bags to the United counter at T7 to recheck them; they'd just put them on the re-check carousel there, and then could reenter security there at TBIT (to go to the *A lounge, as stated) and walk airside to T7.