It's only expected if you buy an Apple.
Having bought hundreds (literally) of Dell/Lenovo/HP business class laptops - I've never had a swollen battery. I've had some batteries prematurely die and have had them replaced (Dell will even put a 3 year warranty on the battery for a small fee) - but no swelling.
Batteries that swell and deform the case are an Apple innovation.
So swelling batteries are magical?