Let me clarify. By "normal" I meant that 90% is not an unusual or undesirable situation. To some extent, an ICU bed is not being used is going to waste; from a hospital administrator's perspective, the ideal situation is 100% utilization at all times with every excess patient smoothly being transferred elsewhere. This of course is unrealistic—you want to leave some surge capacity (thus my 90% figure) if possible—but, generally speaking, a hospital will transfer excess patients elsewhere (either within the same system, or to others in the region), and accept others' excess patients to fill up its own empty beds.

COVID19 patients are not making up a large percentage of ICU patients at the moment; see, for example, the hospital in the aforementioned article with 100 ICU beds. Yes, the 100 beds are full at that moment, but only seven are COVID19 patients; no doubt some other fraction are patients who put off procedures during the lockdown. That hospital is sending new patients it can't handle elsewhere, and will also move some existing patients elsewhere when practical/safe. This is possible because there is no overcapacity on a regional or statewide level.