Acording to a Statement post on the official exodus forum Steve Squievel, and clered that the tour is postponed(and not cancelled) here is the post:

"As recently released EXODUS have had quite a major
line-up change with the firing of lead singer, Steve
"Zetro" Souza and due to complications with
replacement singers EXODUS have had no choice but to
postpone the current dates for South America until the
band can return in late October with touring singer,
Steve Esquivel, of Skinlab.

Top Link Productions did a phenomenal job creating a
successful tour for EXODUS fulfilling all of their
obligations and providing the band with a great run of
dates. Therefore EXODUS would like to extend their
deepest apologies to Top Link Productions, local
promoters, booking agents and all EXODUS fans planning
to attend.

Please keep checking EXODUS' website
www.ExodusAttack.com for the rescheduled dates. Below
are the dates that are currently postponed."

http://www.exodusattack.com/phpBB/

Band profile:

Exodus