I can not explain it, nothing has been changed on the BDD bosses apart from 1 of them.
Random is random it works both ways.
I have noticed stuff like this on other servers that I have played on, once one type of item drops, a few more tend to drop, I always put it down to player killing bosses more as items seem to be dropping.
But trust me I have not changed the rate in which these weapons drop.
Wait a few days and there will more then likely be a 'why did you nerf the drops thread'
Drops are fine, the server is 5 months old, the monsters that are dropping these weapons have had the same drop files for near 2 months.
BH