Smith has been linked to LIV since his victory news conference at the British Open when he reacted angrily when asked about it and has refused to deny reports he has agreed to join the breakaway series.
McIlroy, who finished two shots behind Smith at St Andrews, reached out to the Australian two days after the Open.
"I would at least like people to make a decision that is completely informed and basically know this is what's coming down the pipeline," McIlroy told reporters on Wednesday ahead of the PGA Tour's season-ending Tour Championship in Atlanta.
"I just don't want people hearing information from one side and not from another."
McIlroy's comments followed an announcement by PGA Tour Commissioner Jay Monahan that top golfers will play against each other 20 times next year and that the bonus pool for the Player Impact Program has doubled to $100 million.
The changes represent the PGA Tour's most serious response to the threat posed by the Saudi Arabia-backed LIV Golf series that launched in June and has lured big-name players away from the U.S.-based circuit with huge sums of money.
World number two Smith, who withdrew from last week's BMW Championship citing hip discomfort, is among seven players who will reportedly be announced to the LIV Golf circuit after the FedExCup Playoffs wrap up this week.
"I've always said guys can do whatever they want. Guys can make a decision that they feel is best for themselves and their families. But I want guys to make decisions based on all of the facts," McIlroy said.
McIlroy, the world number four and one of the most important voices for the PGA Tour amid the threat from LIV Golf, was among golfers who attended a players-only meeting last week.
The Northern Irishman feels having the best golfers play against each other more often will create a more attractive product.
"When I tune into a Tampa Bay Buccaneers game I expect to see Tom Brady throw a football. When I tune into a Formula 1 race I expect to see Lewis Hamilton in a car," said McIlroy.
"Sometimes what's happened on the PGA Tour is we all act independently and we sort of have our own schedules, and that means that we never really get together all that often.
"What came out of the meeting last week and what Jay just was up here announcing is the fact that we've all made a commitment to get together more often to make the product more compelling."
