Yes, experimental questions will include RC questions. GMAC is constantly writing and testing new questions.

Because each new edition of the OG keeps the same questions (and question order) with each passage that is retained from one edition to the next, we can infer that GMAC probably does not write new questions for existing passages, but rather writes and tests new passages with all new questions. Therefore, it's likely that one entire RC passage and all of the questions that go with it will be experimental.

However... there is never any way to know for certain which questions / how many questions are experimental. So don't expend too much time thinking about it!