21/ OA for AI summaries is desirable in at least two cases: (1) when the primary sources are paywalled and (2) when the reader wants to skim.
In the first case, note that deposit of the full-text primary source in an OA #repository (#GreenOA) is better than OA to an AI summary. At least that would support studying not just skimming. But of course full-text green OA is entirely compatible with OA for AI summaries.