New Hearthtone changes (relevant to SE's future)
Set rotation isn't just something that encourages business, it helps keep power creep to a minimum because you get an almost clean slate each for each time the rotation would happen.
Do I think this would be good for shadow era? Yes, I actually do. Not yet, but in the future when there are more sets, things will become harder to balance because of the quantity of things to balance against, meaning development times could potentially be longer.
Do i think it will happen in shadow era? Probably not. As lucrative as it would be both development and business wise, wulven seem very dedicated to providing the experience players want, and we all know set rotation for the majority of people is a turn off.
New Hearthtone changes (relevant to SE's future)
If rebalancing is needed in SE, I think restricted errata is better than set rotate. Until release of next 2 or 3 sets, cards are set in stone. After release of next 2 or 3 sets, errata is applied to follow up the new mechanics and concepts. After the errata, the cards remain the same for next 2 or 3 sets again. I hope Kyle to consider it.