Does it make a difference where I save places?
Those are the three "core" lists that Google Maps supplies and I guess that theoretically they have different purposes.
The main difference is about the options available for each list, for example, the
Favorites can't be hidden from your map, and the
Starred places can't be shared.
The available options:
Want to go
edit options is of course available for all lists, and the
delete options is available only for user-created lists.
So it makes a difference where you save it only if the available options make difference to you for different scenarios.