The reason why the PlayStation 3 version wasn't released outside Japan until 2019 was because of how difficult it was to release the Xbox 360 version in all major territories simultaneously. In Hideo Baba's own words:
"Tales of Vesperia was the first title in the series which was planned to be released simultaneously in Japan, North America and Europe. This was very difficult, and it was such a heavy burden for the team. So for the PS3 version, it was decided to reduce this burden and to develop it just for Japan."