This is an ANA aircraft, which means it's probably maintained well and flown by competent pilots. Looking forward to a good analysis on this.
Most large aircraft have a "weight on wheels" switch, activated when the aircraft is on the ground. There might be some bad interaction between the "weight on wheels" sensing and the thrust reverser protection. Pure speculation: initial touchdown, pilots deploy reversers, small bounce into the air, weight on wheels switches open, engine controller detects flight condition with thrust reversers deployed and shuts down engines.
The other side of this kind of failure is dealing with unintended thrust reverser deployment in flight. Here's an overview.[1] Historically, it wasn't a big deal at altitude, but on some newer aircraft, it is, and so stronger steps have been taken to avoid it.
[1] https://lessonslearned.faa.gov/ll_main.cfm?TabID=3&LLID=34&L...