Boba Fett does not even need Morrison's voice to be plausible as a Jango clone, anyway. When Episode II came out I assumed that the reason they chose Morrison was because his voice sounded close enough to Boba Fett's except with a Kiwi accent. Boba Fett has been separated from his father for 26 years by the time ESB takes place, so why would he have the exact same voice? Wouldn't he have probably picked up a different accent during his travels, especially since he was still a kid when his dad died (and kids are able to ditch accents a lot more readily than adults)?

Seriously, the change was totally unecessary and it detracted from the character. Morrison literally phoned in that performance, and it does not sound like Boba Fett. It sounds like Jango Fett, and I do not want Boba and Jango to be treated like they're the same character. The connection between the two characters worked fine before Lucas started mucking with it, and I'd prefer to think of the Morrison dub as an unfortunate accident that we're all best off forgetting ASAP.