A lot of it depends on where he works.
If he works in a skilled, white-collar job that requires very specific skills or degrees, then yeah, that’s no problem to signal. It’s considered polite-- “Hey, I’m six months pregnant. I’ll stay home with the baby after he’s born, but if you’ll let me bring him to the office, I’ll stay long enough to get y’all through summer reading.” Or, “Hey, I’m getting married in November, and we’re moving 200 miles away, because that’s where his job offer was. I’ll stay until [date], but my last day will probably be in mid-September, to give me time to get relocated and find a job in the new city.” Because people with the skills and education to match yours just don’t grow on trees, so a few months’ notice is polite.
If he works in an unskilled job that hires any warm body, then, yeah. You keep your business to yourself. You give your two weeks’ notice, and you’re not surprised if they say, “No problem. Don’t bother coming in next week.”
But if he’s undergoing training that costs thousands of dollars, that gives me the impression he’s not just a grunt working the Tyson chicken line, or someone who’s working the drive-thru, or someone who’s waiting tables.
Leaving my City job for another city 100 miles away was the only time I left with only the minimum notice. I was a secretary— but my boss knew I was dissatisfied at not being able to use my degree, and when I started taking occasional days off (to go to an interview, or to look for a house to buy), he was able to guess at what was coming even before I said anything. Because he was smart.