O'sensei was fine with new ideas and changes/improvements to Aikido. However, I don't think we can stray too far off the road that he established to be called traditional. Mixing Aikido with Monkey Kung Fu won't be considered traditional.
Only thing is, the "too far off" thing gets tricky - "too far" tends to change depending upon who you're talking to.
Was Nobuyoshi Tamura straying too far? Some people think so.
Was Kisshomaru straying too far? Some people think so.
I think that Kenji Tomiki probably thought that he was staying faithful to Ueshiba and his tradition, even though he had his own methods.
I'm fairly sure that Nishio thought he was faithful - and that many of the more "traditional" instructors were losing their way.
Another example - Morihei Ueshiba was OK enough with what Yukiyoshi Sagawa was doing to invite him to be an instructor at Aikikai Hombu.
But now many people consider what Sagawa was doing to have been from a "non-Aikido tradition".
And so it goes...