Aikido schools and instructors, indeed most martial arts, are often asked: do you teach the "traditional" version of your art? This is a tricky question to answer, because traditional means different things to people.
Some view traditional in that the techniques and forms shown are kept to the old ways they were practiced and taught generations ago, unmodified or adapted over the years. Some believe that a martial art gets watered down over time, and believe that old ways are superior to new ways. This does happen. Meanwhile, others believe that modern means 'state of the art' techniques which have greater refinement. Both of these views are partially true but each have their shortcomings. On one hand, there was a time when virtually all martial systems were battle tested and proven to do what they were designed to which was prevail in a conflict. Over time, and a lack of constant use and testing, a martial art can lose touch with its warrior heritage. On the other hand, to say that a given art does not or should not grow to include other effective techniques or practices is a disservice to the concept of growth and innovation.
In the aikido community, traditional often means aikido handed down from direct students of students of o'sensei with the traditional techniques from the founder himself. In the forty years since his death and the progression of aikido, I'm sad to say that much of aikido has strayed far from the intention being a viable self-defense martial art. Back in o'sensei's time it was not so, but has softened since then - so much so that it has become a source of ridicule.
I cannot blame those who scorn aikido because of the charlatan instructors out there, some of whom are high ranking within the aikikai, who indulge in nonsense practices and teach techniques which have no basis or application in self-defense or dealing with violence. They have unknowingly, over a great span of time, invented a stylized interactive dance which lack martial fundamentals. I'm extremely disappointed to see an extremely effective art decay into a pale shadow of its former self.
To my mind, traditional means that a martial art is still effective in a self-defense setting. Modern versions are the stylized and blunted versions which focus on other aspects (sport, fitness, focus, balance, coordination) but lack the fundamentals of what makes them effective martial arts. It is fine to pursue such interests as long as you are clear what you want and what you are getting.
Many martial artists tend to tone their practice down with age, usually due to the wear a body takes as it grows older. It is fine for a fifty year old man to train less vigorously than a twenty year old, but both should train with efficiency and effectiveness in mind with a goal of having solid fundamentals of strategy and combat. When you train with these in mind, you are training in a more traditional way. I believe there is always room for refinement and improvement within an art. In that, I agree with Bruce Lee who was a relentless innovator.
Modern aikido can evolve so far as to become unrecognizable to its core mission. This has less to do with the techniques themselves, but with the intention. Any aikido instructor who teaches that causing pain and injury is the way to create peace or that violence is what establishes harmony has missed the core principle of aikido - that being that the goal of aikido is to restore harmony with the least possible pain, injury, or hopefully without violence at all.
If you wanted to pin down the traditional aspect of aikido, this would be it. To go back farther than aikido one would need to look at Daito Ryu Aikijujutsu, an art that was purely about ending a conflict as quickly as possible without much concern about what happened to the attacker.
Some things to consider in regards to traditional aikido.