If companies that still used plastic spools are starting to switch to cardboard, I think that's a good thing. Not only is it easier to recycle, but probably also lighter (your typical 1kg filament spool weighs around 200-300g), so the bulk should save some fuel for transportation.
Though I personally prefer using no spool at all (during shipping) 😉 Wherever possible I buy Masterspool refills.
Uh, that would be deceiving marketing, a 1kg spool should contain 1kg of filament...
But hey, maybe my view on this is a bit warped because I only buy filament from reputable brands (and usually from their own store) and not from marketplaces like "big A" where hundreds of sellers battle to be the cheapest.