They are living animals. Who knows what will actually happen? It could be good or it could be bad.
I think space has a lot to do with it. One way chickens have learned to get along in a flock is that in case of aggression, the weaker runs away from the stronger or just avoids them to start with. A lot of the time where there are serious problems there is just not enough room to run away and avoid or the weaker gets trapped against a fence or in a corner, something like that. Sometimes the aggressor is really aggressive and will do some serious chasing to do damage, even with room. This kind of stuff does not come with guarantees.
It really doesn’t matter if the space is in a coop, coop and run, or they free range and sleep in trees. What is important is that the space is available if he needs to run.
Different chickens have different degrees of aggression. I’ve had flocks where the broody is pretty laid back and lets her one or two week old chicks mingle with the flock. Occasionally one might get pecked if they invade the personal space of an older hen but a lot of the time, they just wandered around without care. My current flock is that way. In other flocks the broody needs to keep her chicks close by where she can protect them. Each flock has its own dynamics.
Eight weeks is usually when I integrate my brooder-raised chicks but I have lots of room. Also, my brooder is in the coop so they’ve seen each other since I took them out of the incubator. I never have just one, practically always at least a dozen and often many more.
If you have space you can try it. House him next to the others for a week or more, then let them roam together. Watch and see how it goes. If your space is tight, it may be better to wait until he is 5 to 6 months old. Hopefully he will be mature enough then to take over as flock master.
What you are proposing is done a lot and usually successfully. Occasionally there are problems. I wish you good luck!
