"Before you can continue using VaultWiki, you MUST remove the installation directory located at vault/install/lib. Doing so will prevent conflicts when upgrading to a newer version."
The only reason I would expect it to show the old phrase instead is if you have translated the phrase. Please check AdminCP > Appearance > Languages & Phrases > Outdated Phrases.
I have checked the ZIP and it includes the correct language file with the new phrase. In fact, the language file doesn't mention vault/core/controller/install at all according to a search for that text.
Please remove the directory named by the updated phrase.
I cannot reproduce this issue.