Not sure what he means with "2000€ share capital", which allegedly is locked.
Typically, you can spend your "Stammkapital" for business purposes (e.g. in a GmbH). It doesn't need to stay in your bank account.
The Stammkapital was required for the UG, and it's very much locked since the whole purpose of that is to take liability.
The blog post does not read as written by someone who has understood the whole legal process, maybe that's where your confusion comes from.