You're likely right. But perhaps in a given ruleset, the result of optimal play could still a be win for one particular side even given that they have to also avoid any long cycles. If that turns out to be true, it must be the case that as you converge to optimal, even if there is some intermediate period where they become more common, after that they necessarily must then get rarer again until becoming nonexistent.
So the very strongest form of that claim - if it were always the case at increasingly high levels that further skill increases made long cycles more common - would be essentially equivalent to claiming you know the result of optimal play - i.e. you've weakly solved the game. Which is a bit of a stretch of a thing to claim as "guaranteed".
And who knows? If it turns out that one side does win even if they also have to unilaterally defend against long cycles, it's also easily conceivable that in practice as you converge to optimal, long cycles don't ever become remotely close to common before the level of play reaches the point where it becomes clear which side is winning for sure. For example this certainly seems to be the case on 7x7, and looks to be increasingly likely on 9x9. Despite the fact that you can construct board positions on 7x7 or 9x9 where long cycles are forced for both players to avoid losing, it nonetheless seems that under both Chinese and Japanese-like rulesets without superko, non-integer komi values are probably outright wins rather than long cycles and it seems there is never a point where long cycles become common in practice as you converge towards optimal.