"...100% horizontal..."
Thank you for the reply Brandinho1. After two days of waiting and some drama, I got a reply via the PR company handling Latam in Brazil. " the aircraft is configured with the older version of the seats." And that was all. No specification if these are the REALLY old angled-flat or the first generation fully-flat seats (Latam is already installing a third generation of those}. In the meantime, after carefully browsing Latam's website, I found a super brief description for their "Premium Business" seats, that claims all their seats are 100% flatbeds ("...100% horizontal..."). Now, I just have to wait. I will tell you more after my flight, on April 11th.