RCA, like almost all othe record company - never used an inner sleeve for it´s records till the late 50´s. Thinking the jacket was all that was needed.
RCA notice that other companies were using inner sleeves, and, well, not to be out done - starting using them. First using a wax paper sleeve that change when it started to promote other albums and such on the sleeve. By the mid-late 70´s, RCA - again like most companies were dropping the printed paper in favor of just using a 'bag' - some with printing, but most without - all to save cost.