OP is also saying that they're waiting on this one, meaning show me the drastic increase in Katrina level events
But OP would be somewhere between oh ... 50 to 500 years too early to make that statement, had they genuinely been talking about in increase exclusively of events of which the frequency is measured in centuries. If OP is honestly "waiting," (after less than a decade), they could not have had the point you raise in mind.
You're using models to say that overall hurricane frequency should decrease. But OP is saying the frequency of Katrina-level will increase.
I've already granted you, that ignoring the connotation and context of what was being said, the strict denotation of "Katrina-level events will ... increase in frequency," is not inconsistent with predictions of lowered frequency of tropical storm formation. Obviously.
However I disagree that OP intended to restrict their observation to that extent, or if they did, it is a strikingly disingenuous way to pose it. I put it to you that the statement "climate researchers [are] claiming Katrina-level events will drastically increase in frequency. (we're still waiting on this one)" is not the clearest way to convey the current expectation that global warming should lower the frequency of hurricane formation. In fact it is liable to convey the opposite meaning.
The two of you don't agree, but your point doesn't rebut their position
If my point doesn't rebut their position then how do we disagree? ;)