He’s saying that Porsche would be the most logical brand to use in F1, which I agree with.
The problem is that Volkswagen don’t own Porsche. They only have a minority shareholding, so they would need Porsche to agree to it. And if they were going to rebrand PURE engines, the Porsche would have to be super-confident about it. If Porsche were unwilling, then I imagine that VW would enter themselves, or enter under the Bugatti or Bentley names (I know VW own Lamborghini, but Ferruccio Lamborghini didn’t want to compete in motorsport as a factory team).
A team without any proper long time goal (apart from being a place where Red Bull can test drivers – which can be easily served differently) and an owner looking for a buyer.
I’m not sure Toro Rosso is up for sale. Rumours that Red Bull are going to get rid of them come so often that you can almost set your watch by them, but they’ve never come to anything. I think it would be in VW’s interests to buy into a team like Williams or Sauber, and run them as a de facto works team, like Mercedes did with McLaren.
If VW did buy Toro Rosso, it would pretty much mean the end of the Red Bull driver program. VW would be under no obligation to run red Bull development drivers, especially since Toro Rosso only does it so that Red Bull Racing can find drivers for their team. If VW bought in and Red Bull was still a race-winning team, then they wouldn’t be taking on rookies, and so there would be nowhere for their development drivers to go.