By the way, can you help me understand what a 'pre-existing condition' is? Literally nobody outside of America has experience with this term.
How could it be otherwise? Insurance was invented to hedge risk. In the case of healthcare, if you literally already have a condition that has known and ongoing costs associated with it, it doesn't make any sense for an insurance company to insure you against that risk – the risk has already manifested.
You’re a legal resident? You have 100% healthcare same as everyone else. There isn’t even a question about pre existing anything
For example many Germans will have experience with it because they have a system that has both a public and a private system. Those with high enough income (around 70k Euros) can opt out of the public system and use the private system instead. Also there are some classes of people that only can get part of their coverage from the public system and so need to buy additional coverage through the private system.
Insurers in that private system can take into account pre-existing conditions. They cannot reject an application over pre-existing conditions but they can charge higher premiums because of those conditions.
Another example is Switzerland. They have a universal healthcare system based on mandatory insurance from private health insurance companies. For that mandatory insurance pre-existing conditions are not a factor, but there is also supplemental insurance available that covers things not included in the mandatory insurance.
The supplemental providers can and do consider pre-existing conditions when deciding whether or not to provide coverage.