I believe Marcus is looking to come 'home'.
He has stated publicly and privately (don't ask) that while he's enjoyed his time in NASCAR from day one, and remains amazed at the equipment he has had at his disposal (again, from the very beginning) Australia is home.
He certainly would not lack or driving opportunities, even if Penske are not involved, but it would be good if that eventuated.
I've not bothered with the V8 series for some time, some of the Granny Rules have soured the racing and TBH, I simply do not have the free time or the inclination to put up with endless advertising.
Doesn't matter if it's 'Free To Air' or 'Pay TV', more air time is devoted to commercials than racing.