Can’t imagine her wanting to sing with an orchestra? Members of her band have confirmed that she indeed wanted to perform with an orchestra.
Not a good fit? Interesting as the orchestrator, Christopher Willis, went to great pains to provide only instrumentals which supported the unique arrangement presented just by her voice.
Here’s how a review from Italy judged the result: "The new arrangements, in fact, appear intense and poetic, but also refined and delicate, respecting the limpid beauty of that voice endowed with so much charisma, yet with so much measured grace..."
It should be noted that according to her piano player, she was the musical director of the group. Why this matters is that the quality of her arrangements rise far above the wonderful but sparse support of her band and are good enough to be imaged by a much larger ensemble. The version of Over The Rainbow released on the SONGBIRD album has strings which she played using an electric keyboard. Judging from this effort, the one which has become her signature, it is safe to say that orchestrations were very much part of her vision even if not fully realized.
Tall Trees In Georgia (Orchestral) promo short
Songbird (orchestral) trailer - Eva Cassidy with the London Symphony Orchestra
That said, I tip my hat to those who like only the original albums and say, "Enjoy those wonderful recordings." I respect your opinion and stand with you in celebrating her musical legacy.
As for me, I’ve ordered a CD copy from the UK where it was released a month ahead of the US. I’m eagerly waiting for my US 45rpm copy which if purchased in the delux edition also comes with a small book. BTW - it was #9 on the UK charts last week.