Karnig
"Database" is kind of a ubiquitous term. Many people assume that it refers to something like a MySQL database or some other SQL variant. While Ryzom does use a SQL database it is only used for player accounting, shard administration and some of the WebIG apps (such as mail and forum...)
The game itself has its own "database" called a "Persistent Database" which is essentially a serialized tree of world objects. There are no tables or queries - this is essentially a raw representation of the running innards of the shard. I think this is where the technical difficulties lie. I took a look at the code to see for myself and even the existing tools really only assist in generating files for individuals to do this manually. The entire effort, as far as I can tell, is basically a manual process.
So between the technical complexity of manually altering thousands of binary files, mitigating conflicts between three shards, and then actually performing the file moves... there's the expertise on how to do it and the man-power to actually accomplish it.
Guessing - but this is probably the problem.
That would certainly explain a lot, must admit my experience of inner workings is with WoW and Lineage2 which are both very much database driven, but if it's a case of it being a huge manual task then I still believe they have to weigh that against the huge loss of long term revenue if they drive all their long term subscribers away.
If they've already genuinely done that and it really isn't viable then in my view this move is a hopeless attempt to save a ship that's already sunk :( They'd be better off cutting their losses now rather than drawing out the inevitable for a short period longer