Yes and No.
A quick test, using Numbers 13.1, indicates Shapes in Numbers do expand to accommodate more text, but that the extent of that accommodation is limited:

The original shape (top left)was selected,and the text shown was entered.
The second shows the effect of adding the sentence 'When…it. The text was first pushed upward to close the space beteen in and the top boundary of the shape, and the shape was automatically expanded downward to fit the added text.
But, as seen in the third image, adding another sentence did not automatically expand the shape (as noted in the fourth image). The text was added as typed, but was displayed only after the shape was selected, and manually expanded by dragging the bottom boundary downward after selecting the shape.
The size could also be changed by clicking Format, then Arrange in the right side bar, then clicking the Height control in the Size section of than panel.
You may want to Provide Numbers Feedback, using the menu item of that name in the Numbers menu, to request this feature be improved in Numbers.
Regards,
Barry