Cote - did you read the thread?
Your questions are easily answered.
"Breastfeeding mums wouldn't switch to formula just because they have a free can of powder milk, I imagine."
That's not the point. In fact, in a disaster situation, breastfeeding mothers do switch - they are separated from their babies, or they feel they cannot breastfeed because they are distressed and injured, or brand new mothers don't try to breastfeed...this has been seen many times in disaster areas which is why the protocols for safe infant feeding have been developed and which prevent uncontrolled formula distribution.
You say:"What about babies who were on formula before the quake?"
There were very few of them - Haiti is a predominantly bf culture and most babies feed for a long time.
" Do you think their mothers, even if they have mums now, can get more at the local store? hmm"
'Hmmmm' yourself....that's where relactation can come in.
"What about older babies who were already weaned? What about orphaned ones?"
They can be wet nursed, or others can relactate for them....and if this isn;t possible, then of course they should have formula.
As has been explained several times.