There are two aspects to this question: what is legally required, and what is the right thing to do?
You as the author of some software have the legal right to be recognized as the author. These “moral rights” are a part of copyright, but their strength varies drastically between countries.
When the software was rewritten, you might still be an author, or you might not. The question is whether the rewrite was a derivative work of your software in the sense of copyright. If the rewrite was derivative, then you should still be credited as a copyright holder. If the rewrite was a completely independent implementation of a software with similar functionality of yours, that is not derivative, you are not a copyright holder, and you have no right to be recognized as an author of that software.
The GPL doesn't really change this – unless the GPL version in question were the GPLv3 and you had made use of the section 7 additional terms mechanism (e.g. (b) “requiring preservation of […] author attributions”). Since that cannot be done retroactively and the project in question is GPLv2, this doesn't apply.
For an open source project, it would still be the right thing to do to credit all contributors, regardless of whether they are copyright holders in the current version. After all, not every project contribution results in copyrighted works: debugging help, small fixes, administrative work, helping users, outreach, …
The right place for such credits wouldn't be a copyright notice but a section in the documentation. Some projects credit the contributors to a version in the release notes. However, it would be extremely odd to later remove attributions.
While I (as a project maintainer) believe such attribution is the right thing to do because it fosters the community around the project, you (as a contributor) don't have a right to it. Opening an issue “please thank me” would be a very bad look.