This, the authorities say, is because doping tests prior to 2005 were not up to the standards of today.
It is stuff and nonsense. In future years today's standards will be seen as inferior, What then? Erase more records.
Many, the majority, of those records will have been achieved by "clean" athletes. Why tar them with the same brush as the suspected cheats. Why not describe the records as being pre 2005 in a similar way to tennis players being described as champions in the open era as opposed to the old amateur days?
There is far too much re-writing of history going on, in all sorts of areas, just to suit the thinking of today.