Thanks Oliver! All of these circulars are circa 2021. I think there was some confusion in early 2023 (around Jan-Feb) as indicated by the TIMATIC screenshot you posted that said that both old and new passports were required (in the event the passport numbers don't match between OCI and current passport) - which I suppose has been removed in the current TIMATIC guidelines. Case in point my wife was denied boarding from SFO on SQ in early Feb 2023 as she did not have her old passport with her and her OCI had not been updated to the new passport number.

My issue is that I cannot produce the old passport even if I wanted to (lost it!) so I'll have to keep fingers crossed no one asks me for the passport mentioned in my OCI. As a backup, I've applied for an e-visa (tourist) just in case.

Update: Found an even more clearer press release from MEA (amazing that they have a press release that is undated!! ) : https://www.mea.gov.in/Portal/Countr..._Advisory_.pdf
Not sure if any airline will accept this as kosher since it has no date!