Another option is to look past what may seem like trivial dialog within the game and leave no stone unturned. But, it is much easier to just claim that someone who is saying something you don't understand is a troll.
Because you're behaving like one. Let's back it up here. You asked a question. You got two responses, and both of us (me and that other guy) said the same thing. "No." (essentially). Rather than accept that as an answer, you put forward another unlikely theory in an attempt to support your first unlikely theory. Once I shot that down, you went off the rails and made it pretty clear to me that you weren't taking this conversation seriously.
I don't like to cavalierly rule out possibilities either, but your theory (in as far as I can understand it) hinges on:
1) The current depiction of Ulysses being just a ruse.
2) Ulysses finally being unveiled as resembling the Courier. Why? Because the developers have opted for the least original "revelation" about Ulysses any writer could come up with. The old "I am your long-lost sibling!" routine. A tired old cliche, rarely seen in contemporary storytelling outside of fan-fiction.
Is it possible? Sure. It's also possible that Ulysses' head might split open revealing a tiny alien inside his skull. That doesn't seem very probable, however, and neither does your theory. If you can't handle your theories getting shot down, then don't put them out there.