I don't think there's an "official" stance on this, and the answer is somewhat a matter of taste. A good starting point is the golden rule from Jon Skeet's guide to asking:
Imagine You're Trying To Answer The Question
For me a good question to answer is:
- Concise. Doesn't distract from the main point with extraneous details or code.
- Complete. Doesn't require follow up questions or mind-reading to be understood by someone familiar with the subject.
So, applying this to your question here, I think it's better to attempt to present each question as self-contained, rather than as part of an ongoing series. More people will get engaged by a question that's readily digestible; and beginning with a back-story adds weight.
My suggestion would be to compose follow-up questions as if the first one didn't exist; or at most, if you think it would be useful, add a link to the previous question for reference, as a footnote.