In places where health care systems are overwhelmed, medical personnel are having to choose to who let in to the ICU, and they've been choosing to let in those most likely to survive, which tend to be young people.

In such a situation, old people are going to effectively be left to die, and it'll be younger people who are more likely to survive (which they are anyway, simply by virtue of being young).

The only old people that are likely to benefit are those who manage to live long enough in isolation to not get infected before a vaccine or effective treatment becomes widely available... which could take a long time.

you’re thinking of just covid-19 cases. but they compete with all other cases for medical care.

if you come in messed up from a car accident and you need 5 doctors to survive, or those 5 doctors can keep 5 covid patients alive each, you’re going to be left to bleed out. regardless of how young you are.

(i’m not claiming those relative numbers are realistic.)

Would they kick out an old person already occupying an ICU bed for a young accident victim that just came in?

EMTALA in the US appears to dominate among a myriad other sister regulations in this medicolegal and medical ethics problem space. The decision should be left to the staff on the ground with the details of the situation at the moment.

An unaddressed gap is medical staff on the pandemic front lines without adequate PPE are still shackled by these rules made for a system that is not overwhelmed by a pandemic. These need to be waived for the duration of the emergency.

No, but a person in an ICU bed will need a lot of other services which might be subject to triage. (Remember that "beds" is a shorthand here - it's not a shortage of physical beds that's an issue, it's easy and quick to build beds.)