Possible datapoint here to support your statement.

Early October: applied for AMEX Gold. Pop-up message appeared, so I cancelled the application.
Late October: applied for AMEX Gold. Approved with no pop-up message. Assumed it was b/c I had increased my AMEX spend, as DoC indicates.
Early December: found out via chat that AMEX decided to deny my bonus even after NOT showing the pop-up message. Chat support gave me a specialist phone line to call in, and the phone representative confirmed the bonus was indeed denied. But he said he is not a specialist, and that there is no specialist phone department.

The reason for denial was because of the same standard pop-up reason - history of opening/closing cards, etc. Nothing to do with manufactured spend (I did not do that); I had not even completed minimum spend yet.

Chat representative said that the welcome offer was linked to my account, and then marketing department decided to deny it.

What's unacceptable is AMEX's inconsistent (and lack of) communication here. They have a pop-up system but seem to randomly display it.