In the US, that does not happen. The expectation is someone only gets terminated in the first year if they are terrible. Unless it’s a tiny startup, such a stint would raise concerns.
I believe Reed Hastings at Netflix has advocated in the past for a hybrid approach "hire fast, fire fast" - interviews can be nearly useless and unfair. See people who are excellent employees but poor "test takers" vs people who are actually terrible and incompetent but can crush an interview.
In my experience you just don't know what's going to happen until "the rubber meets the road".
That's an over generalization. I've walked a few people out the door within the first 3-6 months who weren't performing that well. They weren't terrible, just ultimately not a fit for one reason or another.
Seems like a good system given the context in the US. Classic American hands off approach that it's more of an unspoken rule than legislation etc :)
But anyway, in many ways I can see a system that like working very well for some of the types of people that need it most (e.g. entry level, neurodiverse etc). Makes the 6 month probation system look harsher by comparison.