WhatCulture! wrote about the possible hint, which Logan dropped at a BAFTA Screenwriters Q&A session:
Rather interestingly, during the talk last night Logan was reminded by an audience member of a quote that he said some ten years ago that, in his opinion, “Bond should always fight Blofeld”. When pressed on this he gave a wry smile and said “Bond should always fight Blofeld”.
Rumors that brilliant but evil SPECTRE head Blofeld would be the villain of Bond 23 have been floating around for quite some time now; at one point, Martin Sheen was said to be in talks for the part. And although Sheen has since stated that reports of his involvement were “absolutely not true,” it’s not all that farfetched to speculate that Blofeld might appear in a some form. Blofeld is arguably the Bond archnemesis, but hasn’t figured in a Bond film since the early ’80s. The timing seems right to reintroduce Blofeld to the franchise, and it sounds like Logan feels pretty strongly about the character.