Can a managed package cease to depend on another managed package?

If I have a Managed Package with Namespace ns2, with package components that depend on / extend components in ns1, then ns1 must first be installed in an org before ns2 can be installed - as ns2 has become an "extension" package of the ns1"base" package.

So my question is: if I remove the components in ns2 that depend on ns1, and then push out a new version of ns2, will the new version of ns2 still require ns1 to be installed? I believe that the answer is YES, but I have not actually tried it before. Has anyone ever tried this?

Example scenario:

1. ns1 has a global virtual Apex Class called BaseController
2. ns2 has a public class called NS2ControllerImpl which extends ns1.BaseController
3. Since the ns2 class is public, I can change the class signature so that it no longer extends ns1.BaseController
4. Assuming that this is the only remaining reference in ns2 to ns1, if I push out a new version of ns2, will I be able to install ns2 into an org without having ns1 installed in that org?