I know patch 4 released Druids but I was hoping that they would have added some of missing subclasses / features / spells from the Player's Handbook along with the Druid.

Cleric: Knowledge, Nature, Tempest, War Domains
Fighter: Battle Master: Many Maneuver, Champion
Rogue: Assassin
Warlock: Patron: Archfey Pact: Blade, Tome
Wizard: Conjuration, Divination, Enchantment, Evocation, Illusion, Necromancy, Transmutation
Too many spells to list but some really core ones like Spiritual Weapon

There are other features like Rogue expertise, etc too.

so we have a bit more stuff to test.

I am a bit worried that other stuff not being added / finished.

If what we have is all we are getting for the included classes, it's a really poor version of D&D 5e.