I've been thinking about this for the past few days, a second new and updated LDraw library. I can see no disadvantages for the library iteself.
However, everything else based on the first library will become, well, useless. Unless the software is being updated of course.
For example, the golden combination of MLcad + LPub (both aren't being updated anymore) for making instructions will become "useless". So, someone will need to make new software for making instructions and the question is if there will be. If not, people keep using the old library (for making instructions in this case) and then the part authors don't see any reason why they should make parts in the new format and also stick with making new parts for the old library.
And, this is just 1 example.
I really like the idea of a new library, but if we make a complete new library, we also need to make a complete new toolset (new software) for all the things that can be done with LDraw models (e.g. making instructions, which is one of the most important ones).
However, everything else based on the first library will become, well, useless. Unless the software is being updated of course.
For example, the golden combination of MLcad + LPub (both aren't being updated anymore) for making instructions will become "useless". So, someone will need to make new software for making instructions and the question is if there will be. If not, people keep using the old library (for making instructions in this case) and then the part authors don't see any reason why they should make parts in the new format and also stick with making new parts for the old library.
And, this is just 1 example.
I really like the idea of a new library, but if we make a complete new library, we also need to make a complete new toolset (new software) for all the things that can be done with LDraw models (e.g. making instructions, which is one of the most important ones).