No, an em-width space between sentences with either half-em or third-em width space between words was typesettig convention for a long time before typewriters, and is where the triple (later double) spacing in typewritten manuscript convention came from.
Typesetting convention evolved to narrower and eventually mostly settled on equal-to-interword spacing after that typewriter convention evolved from earlier typesetting convention.
No, an em-width space between sentences with either half-em or third-em width space between words was typesettig convention for a long time before typewriters, and is where the triple (later double) spacing in typewritten manuscript convention came from.
Typesetting convention evolved to narrower and eventually mostly settled on equal-to-interword spacing after that typewriter convention evolved from earlier typesetting convention.