I have no idea where this info is stored as the details on my billing / shipping addresses have my correct (full) name.
So it's better for them to send a mail to LongName LastName than to LongNameSomethingHere where the last name fell outside of the tag
And as your card shows, the full name is on the DB
If your name tags don't work with slightly longer names, your name tags are broken, not the names.
OTOH these days I'm happy when receiving mail from the US if the address wasn't mutilated by converting Unicode to ASCII or using HTML escapes. Especially when ordering things to my company address, which has an ampersand in the company name and an umlaut in the city.
They're doing exactly what you mentioned in the first line, so big names are identifiable on letters with size limits for the address