@SciresM has added support for Switch firmware 6.2.0 key generation to hactool v1.2.2
The quote below is from his Twitter:
The new tsec_root_key was retrieved through an unpublished exploit and these changes were made to add support for the new firmware. Originally the keys were still being kept private but about two weeks after this news came out, all the CFW's out there including SX OS from Team-Xecuter got updated to support v6.2.0 so Nintendo lost again the battle to prevent 'piracy' on their Switch consoles!
NEWS SOURCE: Switch FW 6.2.0 keys out in the wild (via) EurAsia
(Our thanks goes to hitman43 for the heads up.)