So theoretically from 1 July 2020 you could fly again internationally to Thailand. But be aware that it could be that the Thai government changes its mind again. And be aware that it could be that the Thai government will have extra regulations for foreigners to enter Thailand. Also be aware that it could be that your home country will have extra regulations on people returning home from some countries.
Personally I would not yet book any flights or holidays for this year (2020) and I would just wait what will happen in following next 2 or 3 months.
Photo below is a screenshot of FlightRadar24 with a KLM flight from Amsterdam to Bangkok, an Etihad Cargo flight from Saigon to Abu Dahbi, an Air Asia airplane on Don Muang Airport and a K-Mile flight from Bangkok to Hanoi. But normally this screen shot would see yellow from all the flights.