Blizzard has responded to Protection Paladin initial feedback providing some insight into the design direction of the spec which includes confirming that Avenger’s Shield is no longer generating Holy Power in Dragonflight!
Dragonflight Protection Paladin Talents
Avenger’s Shield not silencing is a bug.
Divine Steed has a bug that increases its cooldown by 15 sec.
Avenger’s Shield is intentionally not granting Holy Power.