Scale of the quiver does not print the actually value till after the figure pop up

All,
This is a follow up of question on matplotlib githup https://github.com/matplotlib/matplotlib/issues/28214

I am trying to print the value fo the automated scale being calculated by the quiver as the following:

plt.close('all’)
fig, ax = plt.subplots(1,2)
axl=ax[0].quiver(x, y, U, V,  angles='uv',scale_units='width')
ax[0].set_title('scale_units=width \n scale='+str(axl.scale))
print('left figure scale '+str(axl.scale))
print('left figure scale_units '+axl.scale_units)
axr=ax[1].quiver(x, y, U, V,  angles='uv',scale_units='height')
ax[1].set_title('sacle_units=height \n scale='+str(axl.scale))
print('right figure scale '+str(axl.scale))
print('left figure scale_units '+axl.scale_units)
fig.tight_layout()

Yet, as printed on the console and shown in the figure title, the scale is None, which I know is not the true value.
Figure_1

After the figure popped up, I printed the scale again, and I got the correct answer.

print('left figure scale '+str(axl.scale))
print('right figure scale '+str(axr.scale))

I got
right figure scale 127.27922061357857
right figure scale 189.83025409097942

Is it expected that we only obtain the true scale value after the figure pops up on the scale? I understand that scale may be among the parameters that is being calculated just before the rending the figure, yet should not this value be available before popping out the figure?
Thanks