Depends on where you are in Alaska. Some of the gravel is very sharp; most not so much. We drove a new Ford Explorer up to Juneau, Alaska in 1993. Had the infamous OEM Firestones.
In Juneau, the problem was the glacier silt used for snow melt was/is extremely corrosive. Ruined bearings and brakes. No problems with the tires until we moved to Kodiak, Alaska in 1996.
Three flats in 2 weeks after arriving in Kodiak. No fun changing tires in the roadside mud while being rained on. Based on local recommendations, switched to 8 ply rating LT tires (8 ply rating was minimum recommendation) with almost an off-road tread. No more flats until the tires wore out over 50K miles (5 years) later, including drive from Homer to San Francisco towing a small boat.
Boat trailer (came with used tires) had tread fall off one tire in Northern BC (at a campground).
If tires are in good shape - decent amount of tread, and not over-loaded - they do just fine. You are not going to be running at high speeds on Alaska roads - unless you want to break your suspension. Sharp gravel is a concern in a few outlying towns. Again, if tires are in good condition, the damage from gravel is windshields and vehicle front surfaces.
To be honest, frost heaves (creates roller coaster roads) and poorly graded dirt/gravel roads are much more of an issue because you want to get to the next town in the same day. You go faster than you should, and the suspension pays the price.
6 years living and traveling in Alaska