Not sure if this is a bug or intentional - Admin Centre Upgrades query

I think the option to upgrade the admin centres is a very nice touch, but is it a bug or deliberate that in one turn I can update every single centre attached to any city?
It was a most pleasant surprise when I stacked up several in a game, expecting 5 turns to complete them all, when they all completed in just one turn!

Is this how it is meant to be?

 

The cost for them is 1 industry each, so it‘s meant to be possible to upgrade all in one turn.

 

That's interesting - perhaps this ought to haver been in the patch notes though, as I reckon most folks will be unaware of this - I know I was until I stacked a few up to save me the agg of doing the same thing several turns in a row, and was amazed when they all upgraded at once.
This is a nice touch