what's the point of him asking me to do something for him that he can do himself regardless of baby or not
OK, you are thinking "why would my son ask me to do something he could do himself - the only explanation must be to that he is LAZY".
But in fact, the reasons children ask for help with things they are capable of doing is because small children NEED the attention and interaction of the adults around them. It's not just a preference, or a desire, it is an actual need. So if a child feels that the attention and interaction of the adults around him is wavering, he or she will attempt to get it any way they can.
Asking for help with tasks is a good "first attempt" that kids make. If that is ineffective, they will move to other strategies - being naughty or destructive, toilet regression, illnesses, etc.
You have to understand that children have a very profound need for adult attention. Evolutionarily, it is literally life or death.
So I understand that now you have a baby, you have less attention and time for your existing child - to you, it seems a no brainer that now your son has to be a lot more independent. But to him, this is not an upgrade.