I think Iron Maiden has it all figured out - they do their own tribute tours.
As for Metallica, check out this set list from Heavy Montreal last summer, based on fan submitted requests...
SETLIST MAIN SET
1. Blackened
2. Master of Puppets
3. Welcome Home (Sanitarium)
4. Ride the Lightning
5. The Unforgiven
6. Lords of Summer
7. ...And Justice for All
8. Sad But True
9. Fade to Black
10. Orion
11. One
12. For Whom the Bell Tolls
13. Battery
14. Nothing Else Matters
15. Enter Sandman
ENCORE
16. Creeping Death
17. The Four Horsemen
18. Seek & Destroy
Not ONE song from any album post Black album, except their new "Lords of Summer".
That's 23 years worth of material obliterated - over 2/3 of their career.
People who criticize would criticize no matter what.