Hopefully someone with better info than me will chime in (my algorithm occasionally coughs up LOTRO vids, but I haven't played seriously in some time). I believe that there are two stated reasons for the situation, both relating to the age of the game. The first is that the remaining player base is not big enough to support the number of servers currently offered, and so consolidation will help the game feel more alive at any given moment. The second reason is that the legacy servers are 32 bit, and they want to modernize to a 64 bit architecture. So, two birds, one (standing) stone.