I think they actually did do an “unlimited” run for CC, they just didn’t bother to changing the numbering or packaging in any way to reflect that because at that point they hadn’t yet figured out how they wanted to do it.
Even with later sets, it seemed rather pointless to change up the numbering system when nothing else about the actual contents of the set changed. Maybe there was some production or supply chain benefit to making the change, like it was somehow cheaper to change it just enough that it counted as a “new” set rather than reprinting more of a previous one?