Having done the Gibb River track you should be fine. Just keep an eye on two things. Make sure that your tyre size (and that you have good tyres suitable for rough stuff) can be sourced at the few places along the route and secondly since the 4G GVs are like a dwarf 3G version make sure you can carry everything you will need
Question for you - why are we discussing a 4G GV? For that matter, what is a 4G GV?
As far as I know, the fourth gens are Vitaras, not Grand Vitaras, and if a Vitara is what the thread starter has (he describes it as a 2017 GV), then this is going to be a whole different discussion - a fourth gen Vitara is a transverse engined cross over, and whilst "All Grip" is an option (in this case "All Grip Select"), it's an electronically controlled all wheel drive system with no low range - it's really not a vehicle I would consider doing any serious off roading with.
I know nothing about the Gibb River track, but below is an excerpt I pulled from the first hit on a google search about the Gibb River track.
Driving along the Gibb River Road is no easy feat– because the road is mainly gravel, at times very corrugated and others is just plain rock – some special equipment is definitely needed. Lonely Planet recommends 'a high clearance 4WD with two spare tyres'.
I'll just point out that neither a third nor fourth gen Vitara/Grand Vitara (or a Rav4 for that matter) can be considered a "high clearance vehicle" (the Land Cruiser you did it in certainly would be), the third gens are to my mind vertically challenged (I own one), and the fourth gens, even more so (I'm currently researching the purchase of one, and the only reason it's actually on the list is that it's made by Suzuki)