Indeed we'll need to see how this all plays out.
I would argue that it is difficult to say how much impact significant naval assets have beyond the obvious naval gunfire support, which I agree would be of limited value so far inland. And to be honest, practically all of the grand strategy ww2 have similar issues (mostly due to scale).
But consider the impact of the presence of the fleet alone---supply ships, hospital ships, radio relays, naval gunfire, massive amounts of AA covering a fair amount of real estate, the list goes on and on, let alone if they have a carrier or two. Normandy is a prime example. The OKW would have probably argued that that the fleets influence (not just naval gunfire) actually extended well into the hexes beyond the beaches and perhaps throughout most of the peninsula. It was a major concern for many reasons. They spent considerable effort worrying about it, and I think it's within the realm of our games (which are abstract anyhow) to allow for such rules, provided they result in a reasonable outcome of course.
Conversely, think of it this way: can you imagine landing in Normandy with NO fleet behind you....just transports? We all know there are a ton of games out there that would allow this.
Either way, as before Michael T brings up good points to consider. I'm actually keeping a list of specific mechanics that I want to look at in detail once I'm able to play. I'll add to this to it. Perhaps once the game is released I'll put out my impressions.