I think I have to go with infinitlight on this one. That doesn't sound like Scully to me. She's admitted to Richard that she's not happy, which he already knew anyway, that she wishes she hadn't left the FBI, and that she's only with him because she wanted "a normal life." That's as close to the truth as he's likely to get. So she's done the hard part of breaking up. She apparently left everything behind, even left her car sitting in the garage. Would Scully have done that without a compelling reason? Would she leave the people who depend on her at the hospital without giving notice? Maybe we're supposed to imagine she can at this point in her life. I'm still unconvinced.

"Sorry to have surprised you like this, but I had to see Scully, and if she knew I was coming, she wouldn't have talked to me."

The obvious question that Richard doesn't ask Mulder or Scully is why? What was so important that Mulder felt like he had to intrude where he knew (or assumed) he wouldn't be wanted? It never gets answered. And without knowing why, it's impossible to make sense of the ending without in effect writing one of your own.