Been here, done that. Not bashing, just mentioning these have been applied to the game and got ruined one way or another:

1. Historical battles was a thing. Was put on hold. Permanently. Historical MM was clogged because everyone just wanted to play with Tiger Is and never launched because the lack of T-34s and Panzer 4s. Also because some people don't understand what 'historical' meant at all. (Can't equip the long 88 because russian bias!)

2. Halloween event was PvE. Guess it's still on test to not make it permanently.

3. Halloween event got them working. And thank god it's not on a real game. Trust me, it's confusing as hell.

4. That'll imply bump the game to T or even M. Not worth to close potential future customers.

5. All rumors but the Italian Tier X might be a wheeled vehicle. For the launchers the idea was scrapped like the Sturmtiger. "Unable to balance"

Only thing I can agree with you is the hull upgrades. It was actually planned to put in game, but I'm feeling the idea got scrapped too. Shame.