In my experience, such dichotomies may be a little misleading.
Aikido seems to incorporate some transferable skills with respect to weapon use. However, a weapon seems to be more than just an extension of your arm. The distancing, timing, relative angles the practitioners are likely to achieve, requisite body mechanics and the overall - for lack of a better word -- tempo of the encounter are very different depending on what weapons and defences you're both using.
I fear, if you try to wield a Jo like a Katana, you're just going to get hurt - just as you'd get hurt if you tried to use a Katana without, among other things, understanding that a lighter more mobile footwork was called for than when trying to wield a fist or to throw someone. Different weights, different penetration characteristics, different lever points, (the ability to rapidly alter your lever points in the case of a Jo,) different speeds at which you can change angles; at least in my experience, they all tend to dictate different, partially overlapping, sets of skills to make best use of the things.
I guess I should have mentioned I am a long time student of the late Shoji Nishio Shihan and our Aikido does not seem to have some "transferable weapons skills"... its all "weapons skills" and just the way it works... Every Technique is integrated so that it can be expressed with all of the weapons I've mentioned. Our Maai, Hanmi, Atemi,and Irimi are different and reflect the use of these weapons. So when you execute Tai-jutsu you always cut, extend and thrust..."Aikido is the Sword" and Shoji Nishio spent his lifetime expressing this philosophy. he even developed his own form of Iaido which is also fully integrated with his Aikido.
I have been to more than my share of seminars over the last 20+ years and can see the difference in our approach to practice compared to others. I hope it does not sound like I am knocking them. How one decides to practice Aikido is totally cool with me.
So instead of saying "Weapons in Aikido" I would say "Weapons are Aikido"