Well, Hattrick is European Football with European football rules and terminology. Buzzerbeater is NBA basketball with NBA rules (as opposed to FIBA rules) and NBA terminology. It makes sense to keep it the way it is, with an explanation in the rules.
Ok ... except that in the end, there will be less "USA" managers than managers from the rest of the world. Let's see how many of them will ask the same question than me ;)
Anyway, thanks or your answers and good game !