Its in no way realistic (even if some hardwood could block blades) but like others said, it is the same for all wooden weapons and all greatly smaller weapons (stick blocking a flamberge anyone?).
It would give archers incentive to melee fight instead of kiting (yes, they still try to kite as much as they can even after the kiting nerf), and they will be able to defend themselves better.
This "melee mode" flag should be on every bows IMO, but with the blunt damage of a wooden stick, so they cant duel meleeist efficiently but can block and finish/injure enemies.
Then, if it "unbalances" the game, just put every bows at 2 slots, so they cant block with a 1 slot bow, 1 quiver, and pull out a danish greatsword out of their asses (which is something some archers already does...).
Also, with the actual weight of arrows, bringing a 3rd quiver with a 1 slot bow melee mode would be a good choice for spamming them, but would be COMPLETELY impossible to kite.
The only downside I see with this is, good archers often just block with their melee weapon, so that would give them even more of a window of opportunity to release that last arrow, then do a quick melee mode block, block while going back and when out of reach, go back to archery and shoot, etc...
So it would need to be perfectly balanced to implement to the game, so that good archers doesnt become super OP / impossible to reach.
P.S.: the video shows the "concept" of melee mode on bows. DAMAGE and SPEED arent decided by matt, he is only suggesting the OPTION TO have melee mode: exact stats will be decided by more responsible persons.