So far Pixelmon has been faithful to the main series games in that regard, making Cherish Balls and Master Balls non-inheritable by children. Both of those balls have a significance in the main series games. Master Ball is the "ultimate Pokeball", serving both as a lore and a unique item. Cherish ball is tied to Nintendo's distributions and events.
However, only Master Ball carries that significance in Pixelmon.
In the context of this mod, Cherish Ball is just a ball that can only be obtained through Pokeloot, (just like Master Ball), but has no other use. In that sense, it's more similar to the GS ball. Staying 100% faithful to the games is not on the table at the moment either, seeing how GS Ball was included, so that change wouldn't affect the mod in that regard.
TL;DR: Pixelmon has no reason to consider Cherish Ball special; We've already deviated from the main series games enough for such a change to be supported; Cherish looks too good to not be used more.