"We don't know what wounds the kids are carrying in their hearts," said justice ministry official Tawatchai Thaikaew, who asked for the boys' privacy to be respected after the discharge, for fear that media attention could affect their mental health.
"The media know the children are in a difficult situation, they have overcome peril and if you ask risky questions then it could break the law," he told reporters.
The group had planned to explore the Tham Luang cave complex for about an hour after soccer practice on June 23. But a rainy season downpour flooded the tunnels, trapping them.
Two British divers found them on July 2, squatting on a mound in a chamber several kilometers inside the complex. All were brought to safety during the three-day rescue, organized by Thai navy SEALs and a global team of cave-diving experts.
Some Thai television personalities joked that the boys' appearance would boost ratings for an otherwise dull show that usually features discussions of the military government's performance.
"This is the story all Thais want to hear. Don't switch it off, don't put it on mute," joked a presenter of Voice TV, a broadcaster that is often critical of the military government.
"It should help the Thailand Moves Forward show's ratings shoot through the roof."
The rescue effort drew global media attention and hundreds of journalists, many of whom left after it wrapped up, but excitement picked up again in the usually sleepy town of Chiang Rai ahead of the boys' much-anticipated appearance.
"The reporters are back. I had to pick up a Japanese reporter from the airport at 2 a.m.," said tour operator Manop Netsuwan.
A cartoon of the group with its rescuers, captioned, "Our Heroes", was displayed on a welcome screen at the airport.
"I pass the hospital where the children are staying every day and I say a prayer to thank Lord Buddha for their return," said Duang, a noodle vendor, who asked to be identified only by her first name.
King Maha Vajiralongkorn has allowed a party to be held in the Royal Plaza, a public square in Bangkok's old town, to thank the Thai and foreign participants in the rescue, the government said.
Earlier, Prime Minister Prayuth Chan-ocha told reporters the celebration would feature a banquet and entertainment, but gave no further details.