Same answer JarodRussell
; "The ship was smashed and needed repair so why not update systems with the latest tech available.
" In universe it is called a refit.
While I do not necessarily approve of all the changes, especially to the Impulse deck, that they bothered to make some upgrades while the ship was in the shop adds a touch more realism than if they'd rolled out the same old design again.
Are we now going to flip out because they took the time and expense to throw anyone who cares about that sort of thing a bone?