So much info to read and too little facts
but parsing through some of the stuff does simplify this down to some meat.
Examination on the ground should be quick and straightforward (no doubt already done) regarding the cowl latches and the condition of the engine damage internal and external. Bird evidence would also be confirmed as yes or no.
The inflight stuff takes a little longer to sort out (symptoms vs response)
The LH engine appears to be operating during landing based on reverser actuation.
The guys taking the video of smoke trails on the f ground also make the comment that it started with flashes of flame before turning into a continuous smoke trail (typical of engine surging non recoverable)
I agree that first flight coming out of maintenance is one of the ingredients to cowls not be firmly latched. I don't recall however, incidents of collateral engine damage leading to a loss of power.
no sense of any further speculation unless/until some new facts are known