I think they have but to what extent is an open question. Maybe 9 months to a year before the launch of what is known as Polaris I (and who knows how many other thousand) frequent flyers took part in a deidentified survey regarding an proposed international business class and what attributes [primarily hard like recline, aisle access, and what to do with the divider between the two seats in the middle of the cabin, with a few soft -- blankets/pillows, meal 'style', etc.] -- while the brand sponsoring the survey wasn't explicitly identified there were a few cookie crumbs that I interpreted as being United-associated.

The final Polaris seat is a very close 'fit' to options the survey offered.

But that said I don't know if UA has ever actually loaded an aircraft with a proposed seat and frequent flyers and gotten their input on the actual product. It certainly doesn't feel like it. The new F seat probably sounds great 'on paper' ("privacy", "more recline", ...) but the sum of the options and execution in the real world is less than ideal. Had you surveyed me on it, I'm not sure I would have caught the most annoying features unless you actually put me in the seat and ran me through an entire [simulated] flight -- trying to get work done (where's my bag?) eating a meal (why can't I actually open the tray table without hitting the person in front of me?) etc.

And the person who thought hiding inductive chaging in the armrest is insane. I wonder (a) how many people use that, and (b) of that population how many people forget that their phone is completely out of sight in a strange location and leave without it.