Liberty Media, the sport's new owner that ousted long-time chief executive Ecclestone in early 2017, is making a lot of noise about the historic milestone.
Ecclestone, 88, said someone told him recently that he has attended "more than 800" of F1's 1000 races.
But he told France's Auto Hebdo: "I will watch the race from London.
"I was going to go to Shanghai, but I changed my mind. A month ago I had food poisoning and I do not feel fully recovered."
'A little frustrating'
Instead, Ecclestone says he will go to the next races in Baku and Barcelona, the latter with CVC's Donald Mackenzie.
He says attending races these days is "a little frustrating".
"It's completely different because I want to be involved but I know I cannot," Ecclestone explained. "I just have to keep my mouth shut."
Food poisoning aside, Ecclestone revealed that if he had still been in charge, he would have re-jigged the calendar to make Silverstone the 1000th race.
"Why? Because the first race took place there," he said. "I was there too.
"If the organizers had told me they were afraid of losing money because of it, I would have arranged something to cover the losses."
Ecclestone said the fact that Liberty is comfortable with China as the 1000th race is due to Chase Carey's inexperience.
'The time of the old man had passed'
"Many more spectators would have come to Silverstone," he said. "I don't know if Liberty thought about that.
"They haven't been in the business long, so they may not have paid attention to details such as the first grand prix in history. They may not consider it as important."
Worse still, he says Chase Carey doesn't even consult with him.
"I am still an employee with this incomprehensible position, but no one asks for my opinion," said Ecclestone.
"Having bought the company, they probably thought the time of the old man had passed."
And he thinks Liberty Media will eventually lose interest in F1.
"I'm not sure they are real racers," said Ecclestone. "The sport is run by business people. They're doing a lot of things I wouldn't have thought about.
"I'm not saying they're wrong, but will they generate more revenue? If not, they should say to themselves 'We bought this to earn money but it's not working'.
"One solution is to increase the races, but then everything depends on the terms of the contracts. The teams criticized the plans to hold a race in Miami, because it would have given the company nothing," Ecclestone said.