Later consensus means an agreement appearing after a question has already been the subject of recognized scholarly disagreement. Legal theorists ask whether such a later agreement necessarily removes the significance of the earlier divergence.
In the line of discussion followed here, the continued relevance of an established prior disagreement creates a difficulty for treating every later convergence as an unrestricted, conclusive ijmāʿ. Other schools and theorists distinguish further circumstances, so this is not a point to present as universally settled.
Example: If two qualified positions were historically established on a question, the later popularity of one view does not justify pretending that no prior disagreement existed. Claims about earlier opinions and later consensus require distinct historical and methodological verification.