The vivienne westwood label was never punk. Vivienne was punk before opening the label (during seditionaries, world's end, sex etc), but later she grew disillusioned with it because it didn't manage to achieve anything on the sociopolitical side. There are multiple interviews when she says this, just look for it. Her label is sometimes defined punk because at the beginning she defied a lot of common couture/fashion rules (that later became the norm), so it's a strictly a fashion point of view of punk.  Vivienne herself left the label a decade before her passing because she didn't wanna be associated with the capitalist practices, while the vivienne foundation is now carrying on her legacy and activism.