With Arrows being alot more rare, i don't really see it as an issue if they did allow it. Though poisons would sort of make more sense and a better way in terms of balance.
Their not rare persay as you might be thinking from what they said early on. I highly doubt it as a scarcity of arrows wouldn't be fair. Rather arrow amounts found/used/sold will be a bit more realistic. With the tweaked archery damage and use you have no need for hundreds of arrows anymore.
Which you could argue is the more traditional RPG way to go. Statistics are supposed to trump realism.
So less arrows for sale probably but still a healthy amount. Probably won't be rare as the word suggests.
Now though availability might be regional. And thinking about the materials needed for sturdy bow and arrows an area surrounded by peaked mountains, full of snow and blizzards, and lacking trees would have low amounts or no arrows.