Wanting to shave my 15month old head..

Bo

He has very thin and uneven hair.. so I am getting it shaved tomorrow.. did anyone share their 1 year olds head and it came back thick and faster? Maybe change texture to curly? I’m the only one in my family with straight hair his dad side all has curly hair too... I know it’s a long shot but it can happen.. how long would it take for his hair to grow back