Christoph Waltz was recently interviewed by German magazine Zeit-Magazin Mann. During the interview he expressed dissatisfaction with his portrayal of Blofeld. He also said he does not know if he will return in the role.

“I cannot claim that I’ve really nailed Blofeld. Overall, it held water and was okay. But it wasn’t what I’ve been looking for. I was searching for more inspiration”, going on to hint that he didn’t quite see eye to eye with the creative team.
Asked about whether he might return in a sequel he replied: “I don’t know about that. Nobody knows. It wasn’t talked about, except in the press”.
Source: commanderbond.net
October 4th, 2016 at 16:06
NOT strictly ‘on topic’, I know, but I was surprised to see Christoph Waltz in a minor role, as one of two German spies, in the 1989 TV movie GOLDENEYE, Fact-based biography of the James Bond author, Ian Fleming. Clearly, Waltz’s connection with Bond goes back further than I’d imagined.