This is what actually happened...
Iona Appliances (which became Fantom Technologies), licensed the dual cyclonic patent from James Dyson. That meant, for EVERY Vectron, Thunder, Lightning, Fury, and Cyclone XT, as well as the Dry Tech carpet shampooer, Iona had to pay James a small royalty.
During the 1990's, Dyson invented MEMA filters (MEMA stands for Maximum Efficiency Maximum Airflow). This is the washable pre-motor filter in all Dyson cleaners. James went to Iona and said "you have the right to use this feature". Iona said "you don't understand. We're in the BUSINESS of selling Hepa filters" James said "I'm not renewing my 10 year agreement with you which expires in October of 2001". (I'm paraphrasing - but you get the point).
After October, 2001, even though Fantoms were selling very well, they did in fact allow the agreement with James to expire. The Wildcat as well as the other single cyclone models were launched.
I was an authorized Fantom dealer and service center in 2001 when the change occurred. I knew that Fantom was soon to be history, so I bought the last Fantom Thunder from Iona then. By November, 2001, I was the USA's first Authorized Dyson Sales and Service Center. My account number was 0001. James himself set up the account for me, and I met with Dyson US's first sales director in my store in Festus, MO
The name "Fantom" was sold to Euro-Pro. Euro-Pro had Sanyo private label the line of machines for them under the Fantom name. Sanyo sold them under their own name as well. These were filtered bagless machines that clogged very quickly with fine dust. Interesting that Euro-Pro has never had a true dual cyclonic (not to mention true multi-cyclonic) cleaner ever. The Infinity does not count as the secondary cyclones are not the same design as Dyson's nor are they as effective.
It wasn't excessive warranty work that killed Fantom, it was greed. The $75 post motor HEPA filter was their downfall. By not having a pre-motor filter (in order to dirty the post motor filter), the motors took all the fine dust, resulting in early failure. How many times do you have to buy a $75 filter to say "no more" to the vacuum?
Of course, in 2002, Dyson's DC07 was launched and everyone forgot about the Fantom.