It would appear that these claims came out of a real estate developer's very unofficial nickname for the Thakhek Dream World City project currently under construction north of Savannakhet in the Khammouane province.
The project aims to develop 507 hactares of land over the course of three phases near a city of roughly 26,000 people. The province itself spans 16,000 square kilometers with an overall population of 330,000 people. Among its ambitions is to bring a "modern and upcoming intellectual township, which has an international financial centre with community development, the first theme park, the first Lao cable car, golf resorts, 4 and 5 star hotels and an iconic tower of a 60 storey-building."
There's certainly room for development here, as the majority of the province is considered forested mountainous terrain. The region has many streams that flow through Khammouane to join the Mekong River.
Among the highlights are the Tham Khonglor Cave (meaning: “Beauty in the Dark”) which is part of the Nation Protected Forest Area in Hinboun Mountain. The stupa of That Phanom dates back to the 5th century, reportedly protected by a serpentine Ngeuak known as Ai Tong Kwang. The Nak Thanamunlanag also reportedly resides in the province.
I think it's hilariously awesome that things can get so strange in Laos that as seemingly absurd as this proposition is, we do still need a confirmation.
Considering how much trouble everyone in the current government went through to end the Royal Lao Government and colonial occupation, suddenly welcoming the Magic Kingdom and all of the Disney princesses, especially the falang ones, would have been quite a stretch of the imagination indeed. History teaches us never say "Never," but for now, I wouldn't bet too heavily on the possibility in the near future.