No, it would be a forced quit, which comes down to an "out of work through no fault of their own." It might take some appealing, running through the system. The employee would have to be very careful to assure the PA unemployment system that they were still in the workforce, still able, available and actively seeking other work for the next few months.
But it would more than likely be a claim for benefits that would have a good chance of being approved in the unemployment world, and the person would pretty much basically get to be off work, draw 6 months of unemployment insurance at the expense of the company for the six months that they'd have been working till next February anyhow, so that's a win for the employee that would make their employer dumb as a bag of rocks. Not saying there aren't any who aren't that dumb, but still, it'd be a good thing, not something to worry about!
The time when notice/unemployment is problematic is when someone announces they're planning to quit, say in four weeks. And the employer jumps it up and says, okay, leave now. Many companies do this just as a matter of policy. Who wants a short termer drawing your money, maybe paying back all old grudges for the next few weeks? Some do, some don't, it's sort of subjective. And whether or not they'd qualify for benefits in this situation is iffy but possible.
This is not the same thing as announcing a planned retirement six months in the future " a decision given to boss to retire in 6 mos" (why, by the way, would you want to announce something like this so far in the future anyway?) This much notice is NOT required anywhere I've ever heard of, and could very easily be something you might change your mind about, want to work a longer or shorter time. Why give so much notice?