TL; DR: Sim, Roddenberry originalmente gostou da ideia, mas não a usou por razões desconhecidas.
O Gene Roddenberry Archives inclui, entre outras coisas, suas anotações manuscritas originais para o espaço Seed script. Roddenberry retocou pessoalmente o roteiro de 7 de dezembro de 1967 escrito por Gene Coon , e escreveu várias ideias para melhorar o roteiro.
Neste momento, o personagem no roteiro de Coon ainda era chamado Ragnar Thorwald:
It will be Roddenberry who fixes the final version of "Space Seed" without credit. Handwritten notes show that Roddenberry had some interesting ideas he wanted to add to the script that unfortunately were not included in the final result.
One that is especially intriguing is the idea that Khan would have a problem with Spock because interspecies mating "might sully the human race." This would have been an especially fascinating theme in "Space Seed" if it had been used, especially considering it is Spock who ultimately defeats Khan’s plans in Nicholas Meyer’s Star Trek II: The Wrath of Khan.
In these handwritten notes is the name "Khan," an ethnicity change which was the result of the brilliant casting of Ricardo Montalban, and the words "Sikh” and "genetically purebred."
Esta e outras trivialidades são discutidas no artigo " The Evolução da Semente Espacial "no antigo site STARTREK.COM.