Yes, It will autocommit the other one.It is best to commit both objects. Autocommit objects are not advisable. Please refer this below documentation for both more clarity on commit & autocommit objects.
Hi, the autocommit functionality as per the documentation works only when you create the association.
Meaning, if you have Object A and Object B, when you create Object and associate it with Object A then auto commit works.
When you want to edit the object B or Object A, then autocommit does not have any effect. You have to commit it separately.
So, it is wise to handle the commit yourself.
It's best to commit both