well vpn is just a short term hide
as a ISP can capture the data packets and store them they can be decrypted later - vpn is only immediate safe and technically makes only sense when you have a time depending transaction - e.g. bank transaction - where parts of the transmission become invalid before you are able to decrypt it
in communication it does not make a difference because I can trace you days later once the job is done
therefore yes it’s possible to track someone for his comments weeks after you placed your statement