Every singe ore node is in fact just a gameobejct. You can spawn them whenever you like with whatever respawn time you want them to use, and they will work.
There is kind of special system on WotLK which keeps ensuring that nodes are spawning in different manner in zones (not jut based on respawn time), based on speed in which they are getting looted by players (afaik those systems can be turned off somewhere completely in config). Thats completely separated system and I don't know where to manage it - never used it myself. What is important is that newly spawned gameobjects are not included in such systems, so you don't need to worry about them as long as you don't want to actually use them for something, or as long as you don't want to change loot nodes settings in some blizzlike zone.