No. T50 had too many flaws.
1. Restricting the usage of rare cards in the game limits the potential of elements.
2. T500 provides a reliable way for elements, and not players, to distribute rares. Farms=bad.
3. T50 wasn't about anything- just who farmed the most. With the new Arena, everyone can participate, and there are 2000 decks of a variety of difficulty levels to play against. Compare that to 50 decks, half of them farms.
4. As you play longer and get more cards, it becomes easier to build better decks. There's really no substitute for that, and bringing T50 back won't change that.