A ridiculous and fearmongering article that misses the key points entirely and deliberately.
In order to recriminalise the use of cannabis they would have to add it back to the category 5 narcotics list from which it was recently removed.
By doing so, they would make hundreds of thousands of Thais criminals overnight. Note that they have just given away a million plants, and it is available everywhere and now a massive industry with products on the shelves of every convenience store and supermarket.
It's here to stay so better just deal with it as it is.