The issue is that IOI have said before that the minimum content to be eligible as a Season 1 owner, including rights to earn basic Legacy Pack, is that you must own:
- Bonus Episode (The Icon, Landslide, and A House Built On Sand)
All other content, particularly GOTY Suits, Patient Zero were part of GOTY Edition (and hence there is a GOTY Legacy Pack).
The 7 above supposedly are part of HITMAN: THE COMPLETE FIRST SEASON. Which was true on Steam PC when I bought that exact version back when Hokkaido dropped in.
On PS+ Europe and Asia it appears that HITMAN: THE COMPLETE FIRST SEASON is missing the Bonus Episode and therefore they all fall out of the minimum requirement for H2 Legacy Pack.
Also I believe all PS+ Asia is based in Singapore, though PS+ Japan appears to be its own territory.
You are correct that the issue does not affect owners of GOTY. But the PS+ Offer right now does not include GOTY.
Tagging @Travis_IOI for follow up. Seems more and more people have this problem.