Are profile datasets merged in CJA?

Quote from a previous link,

https://experienceleaguecommunities.adobe.com/t5/adobe-analytics-blogs/how-to-leverage-event-lookup-and-profile-datasets-in-adobe/ba-p/681478#:~:text=Profile%20Datasets,-Profile%20datasets%20in&text=They%20serve%20as%20a%20repository,specific%20reporting%20timeframe%20in%20CJA.

"Another important characteristic of Profile datasets in CJA is their lack of temporal tracking. Instead of tracking state changes over time or being tied to a specific point in time, Profile records in CJA reflect the most recent user data. Operating on a last-value overwrite basis, new data replaces any previous data. This ensures that Profile datasets always represent the most current state of the user's data."