I haven't seen anyone say Middleton was not really in Vegas. And Boras is too, supposedly.
I also think Passan just chose his words poorly. "Meet and greet" is too casual. But it doesn't have to be a "sign and fly" either. What this is is the beginning of the real final negotiation. It could take 24 hours, it could take two days, it could take another week. But he doesn't have to get on the plane tomorrow.
Reports of other teams still trying as per Heyman, sure, whatever. It's hard to imagine the Phillies walking away w/o meeting their number when they obviously were willing to let Manny go due to a preference for Harper, not "valuation."
The fact that there might be a gap between what Middleton wants and what Klentak wants (I wouldn't put MacPhail in either camp, his job is to tell tickets as much as it is to win games) is not ideal, but I don't think the point of disagreement is large enough to matter. If Middleton wanted to sign either FA and Klentak doesn't want to, that would be a bigger issue if the GM isn't allowed to do his job. But if Klentak merely preferred Manny (for very valid baseball and $ reasons) and Middleton prefers Harper (for also valid baseball and revenue reasons) that's okay. If Klentak had wanted Manny badly enough to stake his job on it I'm sure Middleton would have let him make the signing, and if Klentak absolutely doesn't want Harper we wouldn't still be on him. Or we'll have a new GM.
"holding out" typically refers to players who are under contract, or want a valid contract ripped up. Philly phans will get over it if and when he signs. They are not going to boo him on Opening Day because he missed a spring training game on March 5.