There were a few ideas for new ores. Few, but valid.
Those new ores could get more uses as time goes.
An example is Tungsten ore from RP2, it is nearly useless now, later it may have some, or lots of uses.
I knew you would use that example, let me break your cloud in there:
Eloraam have planned every single feature that it will come from this PR4 to the official release, that includes the uses for the 3 gems, silver, tugnsten and similars. She decided to add those ores earlier so people didnt had to make new worlds with the official release.
So no, she did not simply say "Oh im gonna add this useless ore, and maybe with some time a few uses will come to me", she must have said something along the lines of "Im gonna add this ore right now because i know what im going to use it for in the future".
The IC2 dev team DOESN'T need new ores ideas, they need new machines and similar ideas and if necessary new ores could be made to make the recipes of those new machine on similar ideas.