Our initial runs exposed a few (expected) issues: the game sometimes crashed, didn’t recognize our modern video cards, and was incompatible with our current login system. That first pass also couldn’t support any of our modern security and anti-cheating capabilities. Clearly we had a lot of work to do to make WoW Classic live up to the Blizzard standard of quality, and deliver the experience players want.
Swim Speed Potions (used especially at lvl 37 for Faldir's Cove in Arathi Highlands and lvl 57 in WPL).  Try to get multiple stacks of these.  I also recommend keeping a stack of these always in your bags.  You will frequently pass rivers and lakes and can use these potions to pass them faster through out the guide.  Please note that these potions do not stack with Druid's Aquatic Form and Glyph of Aquatic Form.
File data: This is often very dense data like 3D models, textures, animations and terrain. Our user interface is built up from XML and Lua files. Many of the art files do not use the same file formats that commercial art tools spit out. Our build pipeline takes these raw art files and translates them into something optimized for our game to read and process.
I wonder if they’ll execute this similar to Jagex does OSRS. Let the players vote and once all phases cleared and of articles have been introduced, vote new WoW Classic articles to be inserted. There are a couple large ones that I think should be changed, like warrior taunts being able to miss and certain classes only being plain unplayable. Changes could correct a number of the issues that are bigger, and eventually the player base will quit seeing these things and just become irritated and need them to be fixed. Give everyone a couple of buy classic wow gold months of nostalgia that is pure , then resolve a number of these things.