I buy Dionex columns and use them on my Agilent LCs. I've never had an issue with anyone even asking what system I was going to run them on. But, those are silica RP columns, not IC columns. If it's a new policy, it's new to within about 3 months ago, which is the last time I bought a column from them.
I do wonder if Dionex will not warrant performance of their IC columns or provide support if it is installed on a system other then one of theirs, like how Waters doesn't support the use of its Acquity UPLC columns with a system other than an Acquity UPLC.