We don't yet know how many Room cards Duskmourn will provide, but we've already seen artwork and names for plenty, with Grand Entryway/Elegant Rotunda, Dollmaker's Shop/Porcelain Gallery, Painter's Studio/Defaced Gallery, and Moldering Gym/Weight Room all teased
So with that summary in mind, lets take a more in-depth look at each type of booster pack
Dragons haven't gotten cheap per se, but they don't all cost 6+ mana anymore there is a solid selection of 3-5 cost Dragons, many of which have haste and are solid beaters
Conclusion At the end of the day, understanding Magic Commander deck types is not about memorizing every possible label or forcing your deck into one perfect little box
However, they will likely restock, allowing more preorders in, before the set goes live