Is there any evidence whatsoever that GM would have considered Hemanth Kappanna an "undesirable"?

As far as I know, they hired him after his participation in exposing the VW scandal. If this exposing is what made him "undesirable", why did they hire him in the first place?

I find it more believable that this is just the usual outcome of corporate restructuring, i.e. layoffs in units.