Certainly, many routine simple enquiries, such as simple enquiries on billing, train times etc, can be dealt with by computers. Also, being able to get almost instant response for routine enquiries enabled by IVR will make people more likely to use call centres. When they do call, even if the computer can't help them on its own, experts systems and general artificial intelligence will enable the operator to give much better assistance. This is the key. Increasing computer intelligence allows a relatively unskilled operator to do what used to be a more highly skilled job, moving them up the value chain.
Computers upskill people.
The other effect of computer intelligence handling routine enquiries is that much of the dull component of the work can be removed. People would deal with those enquiries that require more intelligence than the computer can provide, more fuzzy enquires that need more human skills, or deal with those enquiries that are more human contact oriented. They will offer the human value add to what would otherwise be a mechanistic response. People working in such centres today are sometimes over-supervised, with performance monitoring software ensuring at first that they do their fair share of the work, and then inevitably that they must achieve targets. This must make such centres stressful places to work.