We discussed this at some length at our local IAEI meeting. As a esult, locally, we are not expected to install AFCI breakers on service upgrades.
One reason was that earlier wiring practices did not segregate bedroom circuits from others; each bedroom wall very well might be fed from a different circuit.
The real kicker was that remodels are often done on homes with obsolete equipment. When the older equipment has no ability to accept an arc fault breaker, the only option would be a complete service change ... which is quite an additional expense, when all the customer wants is another receptacle!
