I clearly don't think they are selling 75K, but they do have reduced attractions operating and a lot of the focus of the events is on Main Street and in front of the Castle which is where people tend to congregate. While it might feel incredibly crowded in those two areas, back by the Tea Cups it might feel empty.
Treed by 5Hfan
My wife and I went to the first party. We arrived at MK about 2:00PM - it was relatively empty. As the night progressed, it got more and more crowded. I can promise there was a crowd back by the teacups.
About 5:45 we got in line for the Dwarves, and we were in that line for two hours (the Dwarves had to go check on the mine about 30 minutes after they came out, and stayed gone for about 20 minutes...). By the time we got done at 7:45, rode Haunted Mansion, hit a few treat lines, and then rode BTMRR, and then went and checked in for the Dessert Party. Took us almost thirty minutes with the crowds to get from Frontierland to Tomorrowland Terrace. We checked in and went and rode Buzz since they weren't letting people in yet (had a 5 minute wait - really a walk-on). We came back, got into the dessert party, ate dessert, watched Hallowishes, left and went to see Mickey in his Halloween costume (posted 15 minute wait - closer to 30). Got out of there by 11 and sat down on the curb at town square for the 2nd parade.
So, for the $274 my wife and I paid to attend the party (including the dessert add-on) we rode three rides, saw the fireworks w/ desserts, did two character lines, and watched one parade. There was no way we could have made it back to our "reserved" viewing for the first parade due to the crowds. I can say that it was a mad-house and while the fireworks and the parade were AWESOME, the over-selling of the event makes me not want to go back. Why should I spend an extra $68 on an event ticket when I could have ridden everything I wanted during the daytime, and then watched the fireworks from the GF Dock or some other place.
If we hadn't of had the dessert party, I'm not sure we would have been able to find a decent place to watch the fireworks without camping out for an hour. The party was very much oversold and I'm seriously thinking about asking for a refund. There were a lot of people in that event without wristbands, and there were only two places in the park to get bands if you were already in (why they didn't have them at guest relations I still don't understand). For it to be a "special, hard-ticket event", it was certainly not limited the way it has been advertised in the past. I was extremely disappointed and it was clear from the reaction of staff members that the MK was under-prepared for the event. Even if the event sold out day-of (which I believe it did), there is no way that they sold 10,000 tickets day of. They had to know that party was close to selling out, yet did not staff it appropriately.