I'm not sure about the specifics of GDPR, but it could be argued that even your style of writing personally identifies you. There are even projects that do just

I'm not sure about the specifics of GDPR, but it could be argued that even your style of writing personally identifies you. There are even projects that do just that to find alternate reddit accounts of people [1]. [1] https://github.com/jabraunlin/reddit-user-id https://github.com/jabraunlin/reddit-user-id