Yes, it does not cover anonymized data or data that does not relate to an identifiable individual. But, if your Lemmy account is associated with a real email address, your comments and account details can be considered personal data under GDPR. The GDPR defines personal data as any information related to an identifiable person who can be directly or indirectly identified, particularly by reference to an identifier such as an email address. Even if you use a pseudonym (fake name), the fact that the account can be linked back to your real identity through the email address makes the associated data (like your comments) subject to GDPR provisions.
Yeah, it’s still a personal data and still considered as such under GDPR. And you’re asking the right questions: Even if a server is located outside the EU/EEA, and if it offers services to people in those regions (e.g., by providing english or german language), GDPR compliance is required. Practical implementation is a pain :)