If we're talking about the power level of classic cards being too strong where Blizzard is unable to print cards that push them out I suggest 1 more not mentioned:
whenever tempo mage shows its face in the meta, you can guarantee that Mana Wyrm is the #1 choice for a 1 drop. Sure tempo mage isn't top tier right now, but if the idea is to keep the meta fresh, then getting rid of auto-include cards that are in the classic set seems like a priority.
Another card which I actually like a lot and seems to make sense to rotate out is:
In about almost any deck that could use a bit of spell damage, every meta sees Azure Drake being played and it will see play for the rest of HS if it is not rotated out. I don't see anything wrong with that, but if you are for a less stale meta, then getting rid of an ever present neutral 5 drop is one way to do it.
Other cards I thought of are just legendaries which I just see people using forever and ever just because I don't think anything has beat out their power level in any expansions:
- Note: I don't personally want any of these cards rotated out, but if you're trying to achieve a fresh meta for every expansion, then removing cards that are "best in slot/class" is one way to do it.