I observed another user having this same issue with resolution.
RE: Assertion fail after initializing task watchdog with hardware watchdog fallback
It appears the watchdog configuration has changed but I'm unable to track down the driver/overlay/etc that changed that doesn't allow this to work. I see the same assertion as in the linked ticket and the same flow.
######################
## Task Watchdog
######################
CONFIG_WATCHDOG=y
CONFIG_TASK_WDT=y
CONFIG_WDT_DISABLE_AT_BOOT=y (tried with and with out this)
CONFIG_TASK_WDT_HW_FALLBACK=y
CONFIG_TASK_WDT_MIN_TIMEOUT=1000
CONFIG_TASK_WDT_HW_FALLBACK_DELAY=1000
Again, I never had an issue in my 2.6.2 project, but now it doesn't work in 2.7.
Thanks,
Gabriel