In my view the Lidl rolls may be baked in-store, but I doubt the dough is prepared from raw ingredients in store. It is far more likely the rolls, pastries etc., arrive at store in an un-baked, ready made, frozen state, with each batch put in the oven to cook. On that basis they can claim they are baked in-store, because they are.
It seems likely to me that the portions have been adjusted at the central preparation factory.
Curiously enough the other day when I was in Lidl, replenishing the AB yoghurt lake, the chap on the check-out till mentioned to a colleague he couldn't stay on the check-out too long as he'd have to fet a bit more baking done. Had he been in since stupid o'clock making several variants bread dough, sweet and savoury pastry and croissant, I doubt if he'd infill anywhere. He'd finish a bit earlier like the posties do.
Where some shops are still producing the larger rolls, perhaps they just haven't used up all the big ones yet, before moving onto the smaller batches.
I could be very wrong, but if they do any more than baking from frozen, I would expect much more variation in size, and quality/flavours from store to store.