A specialist lawyer paid to investigate the subject and write their legal opinion says GPLv2 can’t be revoked (section 7.4 GPLv2 Irrevocability):
https://copyleft.org/guide/comprehensive-gpl-guidech8.html#x...Of course, many other non-specialists have contrary opinions. If you have a link to a legal opinion to the contrary (by a lawyer skilled in the relevant areas), could you please share it?