The AAIB update states that effort has been put into retrieving the data. Well that suggests they have it, and that it has allowed them to draw a number of conclusions which in the scheme of things they have to gain a level of stakeholder acceptance to.
So the black box - if it was fully and appropriately configured might have yielded the same information, in a more easily retrievable format.
The crash would have still occurred, the report would have been a little quicker - we are a year on and the AAIB are suggesting it will take 6 months of stakeholder engagement to get a final report. So the right black box might have reduced the time to a report from 18 months to 12 months.
Given the modest number of people exposed to the risk and the eye watering cost of retro-fitting this type of equipment it seems an very inappropriate use of the money.
Much more cost effective to sort the mechanical/electrical issues if there were any and then move the training / competency requirements to try and stop it recurring?