Can the bonus action attack from Polearm Master be used to Disarm?

Question

Polearm Master (PHB p. 168) gives you the ability to situationally make a bonus action attack:

When you take the Attack action and attack with only a glaive, halberd, or quarterstaff, you can use a bonus action to make a melee attack with the opposite end of the weapon. This attack uses the same ability modifier as the primary attack. The weapon's damage die for this attack is a d4, and it deals bludgeoning damage.

The optional Disarm rule (DMG p. 271) allows a weapon attack to disarm rather than do damage:

A creature can use a weapon attack to knock a weapon or another item from a target's grasp. The attacker makes an attack roll contested by the target's Strength (Athletics) check or Dexterity (Acrobatics) check. If the attacker wins the contest, the attack causes no damage or other ill effect, but the defender drops the item.

Can you Disarm using the bonus action attack provided by Polearm Master? (obviously forgoing the damage roll).

Answer 1

Yes, you can Disarm using Polearm Master's bonus attack

Disarm only requires a weapon attack to use it:

A creature can use a weapon attack to knock a weapon or another item from a target's grasp.

And Polearm Master's bonus action is a melee weapon attack:

When you take the Attack action and attack with only a glaive, halberd, or quarterstaff, you can use a bonus action to make a melee attack with the opposite end of the weapon.

There are no general or specific rules further limiting the use of either Disarm or the bonus action attack. Thus, there is absolutely no reason why this should not work according to the rules.

Answer 2

Yes

I have seen nothing specifically disabling this in the RAW. Considering the extra attack comes from a class feature, I wouldn't even exclusively hamper this ability due to the unexpected nature of multiple attacks. It is also worth noting that the "Disarming Attack" maneuver is distinctly different from the DMG disarm if that ability comes into play.