What would happen is Osensei came forward in time to visit your dojo (with the best language translater if needed)?
I know we are all thinking he would obviously just join class, take ukemi, thank us for our time, and go have a beer after class to BS about how pleased he is with us doing his art and representing his life's work so well.
For me, of course I'd toss him around a bit and show him all the improvements I've made!!!
But for the sake of it, let's leave out all of the "I AM doing the only true aikido" and focus on the what if Osensei didn't approve...
part a: Names:
What if he saw what you were doing, was outraged, and demanded you stop calling your art "aikido". What name would you call what you are doing?
What if he did that so often that he decided - forget it, I'll make a new name for myself. What name do you think he would chose next for his art?
part b: technical approach
Would even that visit get you to change your entire approach? If for instance, Osensei saw your kotegaeshi and said what hell are you doing? That is terrible! Never do it that way again! Here, let me show you - and then showed you how to do it in a way that you hated. Would you fall back on what you are comfrotable with the moment he left the dojo? How about if that happened with every single aspect of what you've been doing all this time.
part c: loyalty
What if he demanded everyone start doing a ton of misogi exercises and most of your students were quitting/dropping out. Would your loyalty be to your students or to Osensei's aikido?
What if he watched your shihan that you've followed faithfully for years and told you that he had trained that shihan wrong as a joke? Would you stay with your shihan who may insist that his (something short of "scrotum to your fist" technique) is the correct and true aikido, or would you move on?
part d: spirituality
What if he clearly explained his view points on aikido and kotodama? I don't know enough about this to even ask good questions. Would find yourselves chanting? hmm, Would you be more or less interested in such aikido direction?
...please come up with more parts yourselves..