the black forge can be teleported. i doubt black metal will see as much use as it did for the mistlands constructions. ashlands has its new metal type afterall.

iron will be used again. its iron. there is just no escape from iron.

we sadly do not know if they reuse flamemetal in the furnace at all or if they just get rid of it entirely and come up with something new.

its also a bit early to prep. we dont even know of the biome landmass will stay where it is or start to spread out when the update hits.

ashlands wont come out until the end of this year. its still atleast 6 months off by now minimum.

for now the thing thats comeing soonish is hildirs quest. ptb for that should begin within roughly 1 month or sooner. this needs some unexplored black forest for the new dungeons to spawn.