Is there anything new to be learned about companion ages? I know the ages are mentioned but are those their ages for when they are recruited, from the beginning of the character's story, or from the end of the character's story?
Any mention or clarification on that with dates or anything?
It is easy to miss, because it is in a sidebar at the very beginning, but it is spelled out explicitly that the date for the beginning of the game, used as the standard of reference in the encyclopedia, is 3640 BBY, thirteen years after the Treaty of Coruscant. So ages of companions are relative to that baseline date.
The encyclopedia does not
map out a timeline for the stories in play, or say over how long a span of time they take place. So that is still left quite vague. Plainly some companions join you later than others, but I would read the age in the profile as their age in 3640.