If backbone providers A, B, and C are fully peering with one another
and little guy X has no peering with A but does with B and C. Will
packets still travel from X(customer) to A(customer) and back again?
It depends whether X has transit from B, C, or some other peer of A.
If yes, then yes. If no, then no.
Because if X just peers with B and with C, neither B nor C is going
to announce X's routes to A...
If this isn't obvious to anyone following these discussions let me
know and I'll write something up for people to look at and hopefully grok,
which should cut down on the noise level.
But noone's talking about cutting themselves off from UUNET.
That's not an option, obviously. Certain other pissing matches
have involved other somewhat-large networks cutting themselves
off from each other and no real harm was done (in terms of
customer-loss - i.e. economic harm) to either network, but that
wouldn't be the case with loss of connectivity to UUNET (or
to a number of others).