It's impossible to know. It's likely he will change. Possibly for the better, possibly for the worse. Go meet him. But also look for and meet some roosters. I know from my own experience if I could do it over, I would have just started with pullets then adopted a mature rooster that had been raised with mature birds. A rooster that had already learned the ropes and proven himself a good flock protector and provider, was gentle with the girls and not aggressive with humans.