In previous discussions on here we already pointed out that the term "Electro" or "Elektro", on a small level, already appeared in context of late 1970s electronic music in France, Germany and Japan. There are some record covers and magazin articles from the time proving it. So recognizing that, the Streetsound label was actually the first to "hi-jack" the term, using it for what really should have been called "Electro-Hiphop" or "Electro-Rap".
The farther one goes from that point the more messy it gets trying track down the ways of the "Electro" term and the styles that went under it in different scenes and areas of the world. It's save to say though that in the 90s the "Electro" term was reclaimed by the electronic music scene. "New School Electro" or "Techno-Electro" as it's still being produced today and its heavily Kraftwerk influenced sound-design character was a new genre that slowly emerged from the Techno underground throughout the 90s.
Along also came a revival of the classic Electrofunk and Electro-Hiphop sound, which ultimately overshadowed the momentum of the new Electro genre to an extend that all Electro using the typical syncopated beats was considered retro and old school. After a short commercial overkill peak with cheesy b-boy Electro even making it into the big charts (at least in Germany) it was over.
The "Electro" term was still around for some time, but it then suddenly also included the upcoming Italo-Disco revival, Electroclash etc. paving the way for "Electro" to be used again as a short term for all electronic music in general. "Our" types of Electro music were left back underground robbed of its name as if it never existed...