It means MP can specialize better than ever before, and a dedicated intelligence and a dedicated strength (gatherer) person will be invaluable for any MP team. Its effect on MP will be fantastic, and let people play specialized roles better than ever before, while still making low level dipping into other stuff easy and relatively painless.
It's effect on SP will be pretty severe. You won't be FORCED into a jack-of-all trades style, but you'll be giving up some SERIOUS QoL perks (like better loot, running/jumping, better vehicles/tools, carrying capacity, efficient self-healing, efficient gathering, and more) if you want to specialize. The ALMOST-required jack-of-all-trades means the top levels of ANY perk will be out of reach until the absolute extreme levels.
It's a concerning trend towards ignoring, or at least discounting SP concerns in favor of MP...similar to how Gazz's go-to answer for complaints about block damage and hordes tearing thru bases was to comment on how he watched youtube TEAMS of players successfully defending on top difficulty levels...which really had no bearing on the SP complaints that were being made.
I'll give it a shot on SP unmodified (probably going to push intellect to 1-shy of motorcycle and try to grab a magazine to craft one, and do trader runs over and over for mods and steel bars, while grabbing a mix of mid level strength and agility, and low level perception and endurance stats/perks)....but I -expect- to personally adjust the numbers If TFP doesn't (i could be wrong, and this might be a comfortable level, we'll see)