`TraditionalForm` is replacing square brackets with parenthesis when it should not

[rocky]

Description

For the parameters of some boxing functions like SuperscriptBox and SubscriptBox, TraditionalForm uses parentheses when it should use square brackets.

How to Reproduce and Output

In[1]:= SuperscriptBox["x", "2"] //TraditionalForm
Out[1]//TraditionalForm= SuperscriptBox(x, 2)

In[2]:= SuberscriptBox["x", "2"] //TraditionalForm
Out[2]//TraditionalForm= SuberscriptBox(x, 2)

Expected behavior

In[1]:= SuperscriptBox["x", "2"] //TraditionalForm
Out[1]//TraditionalForm= SuperscriptBox[x, 2]

In[2]:= SuberscriptBox["x", "2"] //TraditionalForm
Out[2]//TraditionalForm= SuberscriptBox[x, 2]

Context and Workarounds

This is a recent behavior. The 9.0.0 does not have this behavior. Are there other forms that use parentheses where square brackets shoudl be used?