From "Tcl and the Tk Toolkit" written by John Ousterhout, it is written (Appendix A, page 433):

The source code and reference documentation for Tcl and Tk are freely available.
No license is required to use them and there are no restrictions on how you use them (for
example, you can redistribute part or all of Tcl or Tk in products). ...

From "Tcl and the Tk Toolkit Second Edition" (Appendix A, page 717):

The source code and reference documentation for Tcl and Tk are freely available.
Tcl and Tk are available under a BSD-style license, which provides great flexibility,
including the use of Tcl and Tk in commercial products without royalties or being 
required to open-source your own code. ...

GPL is not compatible with the BSD-style license. Commercial products containing proprietary or closed source software, must have the freedom to interface and morph the open source as necessary. That is the intent, IMO, of Ousterhout's original "no restrictions" statement.

I find that the statement presented by the representatives, at the TCT meeting, simply reiterates and confirms what has always been true of the Tcl and Tk code base.