I don't think the non-involvement of MJF is an issue... it was always going to be doubtful that he would take part, all things considered. On the other hand -
there's one character unrevealed on the website. All we see is a sillouhette (sp) which looks very like Marty. Perhaps alternative/evil Marty from another timeline? Perhaps he might only appear briefly, with a slightly different voice?!
Originally Posted by Angel Summoner
The Wallace and Gromit games by TellTale didn't feature Peter Sallis (Wallace), but the stand in sounded just like him.
I thought he was very good, but the voice came and went a bit. Although - is it true that Telltale didnt case him per se, but that he was Aardman's official stand-in, voicewise, for Sallis, already?
As to this business with Tom Wilson, I don't think it's worth our speculating and apportioning "blame". There is a story that Paul McGann's agent (NOT Janet Fielding, though) refused to pass on offers from Big Finish to reprise the 8th Doctor on audio - the first he knew of it, it is alleged, was when he answered his agent's phone!