Yes I'm very aware of how the ATP is run. Are you familiar with the fact that the players are the ones who got the exemption for top players that allows them to skip one of the mandatory Masters without penalty? The number of players that don't go to Monte Carlo now that its not mandatory (even though it offers those same points and prize money)? They are not cash and points hungry mercenaries, they still prefer to have some amount of choice and control over their schedules.
The players will not agree to adding another mandatory Masters event to the schedule, so one of the existing Masters will have to be bought and moved (the ATP will not do that again unless someone volunteers, after the very expensive Hamburg lawsuit).
Let's pretend that happens, and a masters event becomes available... after Wimbledon? Nah, no player will agree to play a Mandatory event right after a slam, so there will need to be a week in between (perhaps Newport and something else on grass, but in what country?), so that puts a Masters in the 3rd week of July. That might work if either Cincy or Canada happens to be the one who gives up their event to make room on the summer calendar, so that there can be two weeks of hardcourt warmups before the next Masters event. It will of course completely screw those clay court events in Europe after Wimbledon (which I've never really understood anyway, but I hear they are popular). Davis Cup might also have to be moved, since they usually play a quarter final week in July somewhere (right after W this year).
I just don't see it happening like that, I honestly do not believe the players will go along with it.
In all of this post you honestly didn't give anything reasonable to your cause, sorry to say.
Let's take another approach. Besides Federer, who in the last years has routinely skipped
some Masters Series events. (And I find it hilariously funny how in all of those cases it was one on clay, and the one in which Nadal has been the most dominant, and the other one in the Indoor season, where Federer has pretty much sucked majorly, as of late), who do you think will skip it?
Nadal, the guy that prays he's not tired in order to play 500's?
Djokovic?
Murray?...
Who?...give me names and tie them with precedents that might have lead to your statement earlier.
As for the whole calendar thing. I repeat, THE WHOLE month of July is free. There are a bazillion 250's that are mostly played by journeymen and players that don't like to get a vacation and there's the infamous Hamburg 500, which is a downgraded past-great tournament that no one really cares about anymore. It is popular, in Germany that is, but every bigger tennis tournament is big in Germany, so that's not a criteria for anything.
Davis Cup?...do we really need to get started on this one?...Davis Cup, seriously?...
Here's how I could sum up this:
-would the calendar benefit from a new big tournament on grass?...yes, surface-wise, and it would also make the calendar look a bit all-round for christ sakes...not a Nadal season + hard courts type a thing.
-would players like it?...oh hell yes, believe me, because grass is different compared to any of the other surfaces so it can bring some "specialists" at the forefront, plus the surface is easy on the joints.
-would the ATP benefit from it?....I think so, purely from the fact that it's a Masters, and the first and only Masters on grass.
-the costs of making this happen, surface maintenance etc could be easily balanced out by profit.