High-elves will not be randomly generated, but they remain a part of the source code.
High-elves are also present in the source code of SLASH'EM. There they are grouped with other elves rather than the quest guardians, but they have a frequency of 0 and so are never randomly generated. It is possible to polymorph into one, however.
High-elves in SLASH'EM have a base level of 7 and an alignment of 9, making them lawful, unlike their vanilla counterparts.