I do not know much about Sweden and Finland, but they have "always" had 230/400V with N
Once in Sweden I had an expensive experience:
We installed same single phase equipment, some PC's etc and suddenly we got a "smoke leakage" The 3 phase supply had a small fuse on the N conductor, so we got nearly 380V at the 230V single phase outlets! Usually they only have fuses/breakers in the live wires in Sweden.
I have no clue about the Swedish or Finnish codes.
