This was my thinking too -- first, I was really pleased to see that snorkel or not, the wading capability is pretty good on this rig. But then I also look at it in the context of the entire event. This is by far the most important event Ineos has done -- every major journalist in the world of automotive news will be taking this Gren through the paces and, based on what we've pieced together, on February 8th those opinions will be revealed to the world. That's VERY high stakes; imagine if even just one of those journalists ended up "dead in the water" due to water ingress into the engine (or any manner of other issue -- electronics for instance); this would be the equivalent of TFL Trucks' Defender saga which I have no doubt firmly hampered JLR's sales of the new Defender in North America. For a rig like the Grenadier, it would be very hard to come back from those first impressions. If you look at discussions on other forums, there are already people lamenting that the Gren is "unproven" and "too technological" by a company that has no automotive experience -- nevermind Magna's involvement, or that there is a minimum amount of technology required by regulation, or that it's using parts from proven collaborators; that detail is not something the general public (even the general 4x4 enthusiast public) are aware of, and so bad press on this first launch has the potential to be a disaster. In this day and age, a viral Tik-Tok/Instagram/Reddit disaster.
But, Ineos has taken Snorkelled and Non-Snorkelled trucks through a proper wade -- not the most difficult one in the word of course, but it's a far cry from the artificial stream/mudpit dug with a backhoe that the JLR experience provides folks when they launch a new rig. There's way more real-world variables in what Ineos is doing on this demo trip -- the car ahead could dislodge a large rock, leaving a pothole that causes the following Gren to drop a fender way below water level; a Journalist can get a bit steer-happy and go into deeper water; even day-to-day conditions on the lake can change the depth of that water crossing (i.e. higher winds). So, over the course of several weeks, Ineos is doing a regular real-world water crossing that comes close to threatening the max wading depth of the rig (and far exceeds the "approved" wading depth of all but a couple of other cars on the market).
The point of all this rambling is: If I were a decisionmaker in Ineos, I wouldn't be going near that kind of a water crossing unless I was supremely confident in the vehicle. The risk of damage from any kind of failure is too great, and this abundance of confidence I think says more about the rig than the photos in the water do.
And, I still want to know how these things drown, because at some point that's going to happen to someone. Can I pull the plugs, drain the oil, and continue on my way like I can with some of the classics? Or does drowning it mean I'm reaching for the InReach? We won't know for some time but the confidence I'm talking about above makes me hopeful about the answer.