A reporter once asked O'Sensei to show him a technique. Apparently the technique was so impressive that the reporter wanted it repeated for the camera. O' Sensei said "sure." He then performed another incredible move for the camera... but it was completely diffrent. After various attempts at asking O'Sensei to perform that same technique again, the reporter gave up and stopped. O'Sensei then asked if the reporter was satisfied. After hearing the reporter complain that he never did that same technique again, O'Sensei told him something along the lines that since the universe was always changing, his technique was always diffrent to match the changing circumstances. His technique was always new, but the principles remained the same.
(I have told this story from memory, on having read it from a book on Aikido, so although some points may not be exact, the basic message I believe has been preserved.)
Effectively, anything can
be Aikido, when manifested with Aiki. So once the basic techniques are transcended, after you reach mushin (no mind), all techniques are spontaneous and new.
My senpai actively encourages forming new techniques. I can hear him telling me during randori, "Forget what you learned and do what comes to you. If its something new, go with it! Relax!"
Personally, I love experimenting with Aikido, but I also love the traditional techniques, for I know that diciplined practice of them will bring me to that spontaneous place I so desire.