On 22 March 2021 the Royal embassy of Thailand in Sweden announced:
Update on Thailand’s inbound travel measures for non-Thai nationals (effective from April 1, 2021)
Please note that other issues such as reduction of the quarantine period to 7 days and measures for those who have already received the COVID-19 vaccine are being considered by the Thai authorities. The Royal Thai Embassy in Stockholm will keep you updated if there is any additional development.
Please also see the link below for requirements for traveling to Thailand during the COVID-19 situation for non-Thai nationals.