Platini said "probably no decision will be taken" on Oct. 3-4, when FIFA President Sepp Blatter has said his executive committee should decide "in principle" that the tournament cannot be played in the Qatari summer.
"In terms of the specifics, we don't know what's going to happen," Platini said of the FIFA meeting which has become the focus of intense speculation.
Platini got unanimous approval for a switch from summer from his 54 member associations this week at a European football meeting.
"We haven't said that we agreed fully," Platini said at a briefing to close the four-day gathering. "What will happen, that's more complicated and it's hard to discuss."
Platini, who opted for Qatar in the December 2010 vote, favours playing in winter and prefers a January slot.
Still, he acknowledged Friday that "maybe it won't be possible down the line" to change from summer.
Opinion in Europe is divided with Platini having to weigh opposition from the influential European clubs, leagues and players' unions who refused Thursday to agree any potential changes in Qatar's World Cup hosting plan before being included in detailed consultation with FIFA.
"It's a complicated discussion, let's let Mr. Blatter carry out that discussion," said Platini, insisting that the whole issue was "FIFA's problem."
Platini appeared to show some frustration with Blatter, who this week repeated an old claim that his former protege was influenced by French political and trade interests to support Qatar, which defeated the United States, Australia, Japan and South Korea to secure the 2022 tournament.
"With the extraordinary experience Mr. Blatter has, he has only all of a sudden realized there are economic and political influences when we decide who is going to host Olympic Games and so forth," Platini said. "It's better late than never I guess."
Public sparring between Blatter and Platini has increased with the next FIFA presidential election due in May 2015.
Platini addressed his expected candidacy when he told UEFA members Tuesday that he would not decide before the World Cup in Brazil. Blatter could use the eve-of-tournament FIFA Congress to announce if he will seek a fifth term, when he would be 79 on election day.
"It really doesn't worry me," Platini said. "I feel very relaxed and happy with UEFA. I feel very much at home here, and I'm seeing how things develop slowly. There's a lot of time."