It would seem that at some time there was a concern that bean/method expressions (expressions in general?) not have side effects on an exchange. Is that not still a concern?
This change negates the whole point of using a copy of the exchange, so wouldn't it be simpler to just not use a copy?
Also, a bean expression that uses a camel ognl expression for the method name will still not propagate state because the OgnlInvokeProcessor uses a copy as well.