The Tcl 9.0 way of how [dfc08326e3] should be fixed: Real integration of TclOO in Tcl means that calling the function Tcl_OOInitStubs() should be elminated in full. This branch shows how to do that.
Eliminate TclOOInitializeStubs() completely. This fixes [dfc08326e3], at least the TclOOInitializeStubs() surprise part of it. 
Further refactoring is possible, eliminating tclOOStubsPtr and/or tclOOIntStubsPtr. A discussion about that is opened on the Tcl Core List. 
This is fully source compatible for TclOO extensions (e.g. Itcl, tdbc) but binary incompatible. 
TODO: update documentation, but that can wait until the refactoring is complete.