I would personally prefer if no additional cards are added to the existing houses and that rather they rotate houses in and out while adding additional houses while maybe guaranteeing atleast one of the new houses be included in decks from each new block.
My concern is that any overly attractive additions to past houses may devalue older decks. Adding new cards risks potentail power creep... And balancing issues.
For example say a new mechanic is introduced and added to the old houses. Welp now all my oldies lack any interaction with this new mechanic and probably feels bad man.
Balancing cards pools randomly beyond 50ish seems daunting and frightens me.... As well as the houses potentailly losing their identity. Plus a ludicrious number of houses just seems more entertaing to me.
I'd rather have a house be broken than the entire game.
Opinions?