That means you'd have to find a voice actor that would be able to play ALL the roles and an extremely competent voice director that would tell him what role he's supposed to play at any given moment. Not to mention, there's still the challenge of making sure that it doesn't seem unnatural when your character suddenly starts to speak differently simply because the player shaped him towards a class.
Unless you mean that your character should ALWAYS speak the same way regardless of what class you eventually choose. That would be even worse however as it would devoid him of any personality. The VA would have to play in a very neutral way and the dialogue writers would have to create very generic dialogues. And even then, some of those dialogues would probably sound wooden and not very fitting considering the kind of character you created. I can't imagine making a single VO that would fit a rockerboy, a corp, a netrunner and a solo all at the same time and still feel genuine and interesting.
I can't see the connection between class and VO. Why should someone's voice change depending on which CLASS he becomes? Why is class so important for VOs here?
I checked it with myself and there was a certain point in my life that my speech has been established for good. The tone, the volume, the accent - they stay the same. I didn't change the way I talk and I already worked in a few places in a few different roles. Why would the VO of my character change, then?
What could be different depending on class are dialogues and dialogue options - for example, Netrunners and Cops each use different slang or approach situations using different attributes (Cop using Authority, for example). But they can be delivered by the same voice actor (he/she will have just more lines to record).