For Base cards: No. All Base cards have the same probability of being unlocked for free through gameplay.
For Silver cards (NFTs): No. All Silver cards have the same probability of being awarded to skilled players via Ranked Rewards (i.e. ranking highly on the leaderboard) or Conquest.
For Gold cards (NFTs): Yes. Every week, eight unique cards will be available as Golds to be won in Conquest. Every week, there will be a new set of eight unique cards that can be won.
The eight unique cards available during a given week have the same probability of being awarded via Conquest. This means however, that after week 1, none of the eight cards from week 1 can be created or won again. So if more Conquests are played during week 2 compared to week 1, the Gold cards from week 1 will be rarer.