Why was this downvoted? The swing analogy is horrible. There’s nothing physical that’s going to change when u play the game the exact same way as 04 05 06. The difference is u know what’s going on as opposed to not knowing where anything is. A good analogy would be playing Pokémon red again after beating the elite 4. The game itself won’t be any worse, it just will be easier and maybe less enjoyable if all you enjoyed is the aspect of not knowing where to go. But this is why pvp servers are magical, because each time you level a character, your leveling experience is different based on the encounters that happen while questing. In 05 U may have breezed through stv, but in classic u may spend an hour on a single quest solely because of the competition between factions on that particular quest.
When it comes to Classic, Blizzard's goal is to provide an authentic Vanilla experience, but they also needed to come up with technology to handle many players at launch, which is similar to sharding. While the use of this technology will be limited to the first month following launch, many players are questioning this decision and wouldn't like to see layering in the game at all.
So even though you can play a WoW Classic demo today, we’re not done quite yet. We have lots of capital city features to look at, such as banks and auction houses. We need to test our dungeons and raids to make sure the bosses’ abilities all still work correctly. We need to examine all of our PvP systems. But we’re committed to taking a close look at all of these and more as continue bring the classic game back to life.