My guess; server and consumer motherboards are very different. BMCs log a lot of data and on startup if the OS driver reads the log it can put whatever it wants in the crashdump. Consumer motherboards mostly only store the reason for last poweroff which the OS can read on next boot. Server MBs may also have a longer timeout before cutting power from a long-press.

Apparently from standby the power-off time on some laptops is much longer and you get a MANUALLY_INITIATED_POWER_BUTTON_HOLD which kicks off in the ~8 seconds from the article.