Is a 4 wheel alignment required when buying new tires?

No... But it's a real good idea to have that done!... Now, if a tire warranty is given and it requires that to be done(?)... Then yes! Bottom line.... It's entirely up to YOU!!

Usually the wear on the old tires will tell you something about an alignment. So after looking at those , they may have seen tire wear, indicating that adjustments on all 4 wheels were needed. Camber & toe angles are the tire wearing angles. And if Camber &/or toe angles are out of specification, the tires will wear quick. That car has the ability for camber adjustments on the rear The front has both So if the old tires showed wear from one or both angles out of spec, They have the option to deny replacement if premature wear brings you back for tire problems and they look back in the records & see you were told about the alignment & refused.