The 25 year hypothesis is only based on the production time frame - there are no documents that link the one with the other. Given that they promoted no anniversary edition, that link will have been loose at the very best.
My guess is that it was intended to be a permanent branding enhancement (probably all across the product line, at least across all their higher value products - I have a Mess Ikonta with that logo, and also have seen Super Ikontas). Perhaps it was prompted by the anniversary, but it may as well have been a mere coincidence. As the white stamped logos on leather rapidly turned grey from sweat and grease, they were dropped again after a while for failing the intended effect.
