ECAM is (quite) clever. It knows that, if you have not pressed the Eng Fire Pb following an eng failure, you have decided on 'No Damage'. Therefore it is fine for the Status Page to suggest:
''If Performance Permits.............X-Bleed ON''
This permits the running of both packs from the live eng bleed with the caveat of: ''One Pack Only if WAI ON'' because the remaining eng bleed is not up to running 2 Packs, WAI, probably Eng AI plus all the other pneumatics.
In the event of a failure with damage or a fire, the Eng Fire Pb is pressed and the Status Page will not make the above suggestion because we do not want to run the risk of hot bleed air entering a damaged engine and/or of contamination of bleed air - depends on where and what the damage is.
Caution! If you are considering running the packs from the APU following an eng fail as called for in the Overweight Landing Procedure, pressing the APU Bleed Pb will open the X-Bleed if it is at Auto. Therefore, if Eng1 has failed with damage, we cannot protect it, but if we are considering Eng2, we can use the APU Bleed, but only with the X-Bleed Closed.
Hope that is fairly clear!!
Cheers
mcdhu