Diego said:

Surprising to say the least, since I remember rumors that he wasn't too happy to have been part of the prequels.

Unexpected to be sure, but rather than being unhappy about being part of the prequels when initially asked, I reckon he was probably more unhappy about how they turned out...

I've never bothered with any of these CGI episodes before (or even the movie!), but may catch them one day out of curiosity. I did like the look of the earlier, short, stylized, animated Clone Wars cartoon series however.