They are taken into custody amid a province-wide crackdown on 'separatist influence,' a local source says.
Activists warn that the move will leave a power vacuum in international human rights issues that China will fill on its own terms.
Heavy fines are threatened for those refusing to take part, local sources say.
Dorjee Gyantsan had gathered information on refugees' names and political views and will now serve 22 months in jail.
No explanation is given for Lobsang Tenzin's early release from a 10-year prison term for 'aiding and abetting' a self-immolation protest.
Pema Gyatso, a student at Lanzhou's Northwest University for Nationalities, had previously been warned that his writings were politically sensitive.
Government employees, schoolchildren, and retirees are ordered not to take part, a local source says.
Fewer teachers able to teach in both Mandarin and Tibetan are being hired, disadvantaging Tibetans, they say.