My 2019 Ford Focus 1.5 St line hit a pothole yesterday.  Just had it checked out a local tyre shop and the rear wheels are out of alignment.  Having 4 wheel alignment check on Monday. 

Does this mean a new rear axle..ouch???

depends how far out the car was -  and how good the tech / kit used

they have to select that specific vehicle spec and follow instructions to set things up to display the correct manu set up - they usually don't get this right and or the software is wrong / out of date

it might be normal - I had a pug - both sides were exactly the same and both outside manu spec - then the tech added there's no adjustment and he'd never had one in spec - it drove straight and didn't wear its tyres funny

the other day a place I use had new gear that didn't ruin the road wheels - and this one now asked if it was the LWB version or not, and to input all fours corner's ride height before starting

1.5 EcoBoost might still have independent rear suspension if registered in 2019.  So arms can be replaced without needing a whole rear axle.