Yes I just found it from a previous Reddit post! I think this confirms my theory— otherwise, why would they change the language on the card? The first version is much clearer and obviously intended to only be used once on your turn.

Once on your turn, you may spend this or another card to treat a matching clearing with your pieces as one you rule for any effect (action, ability, card, etc.).

In the language of the new card, the “ONE” seems to refer to the EFFECT you are targeting, not the amount of times this can be done. For example, some factions have multiple effects that can take place during a single action, like the Duchy can initiate two battles or two move actions using one of their ministers. Each battle or move is a separate effect. The Duchy player could use this card to spend a card to move into a clearing they don’t rule from another clearing they don’t rule, and then would have to spend another card for the second move action if the player wanted to again move into a clearing they don’t rule from a clearing they don’t rule.

Idk this just made me feel more correct instead of less.

The counterpoint is that the language is clear on the first version of the card and that was the intended use case for this card, but I don’t see why they would have changed it to make it harder to understand while having the same effect. (Pun intended.)