Whilst of course the AAIB report is only interim (and the full, final report will no doubt go into much more depth and detail), it seems to me shocking that their only recommendation do far is to reiterate the need to check the cowl latches on walk-around.
There's clearly something fundamentally wrong with maintenance procedures if mechanics can simply forget to latch the cowls, and presumably with no supervisory check on this.
This is going to happen again, quite possibly with dire results.