I noticed an update in the corechanges (099) :
Why this change?
Will be there an option like "SpellsUnhide 0/1" in config files?

Thank you.

That change, and the one to SpeakPowerWords(), is to allow more control via scripts for this. You would need to check and unhide in scripts if you want the spells to unhide them

Yay!
Anything you can do to give scripts control is good.
I thought that unhide was added some time ago though, like in 0.97. I guess not.