Not quite, EA lifted the concept from mobile gaming by-and-large. Loot box mechanics also were commonplace in Japanese and Korean MMORPGs long before any game included them stateside, console or mobile. In addition, Zynga had a hand in popularizing the model stateside well before EA touched it with their free-to-play games on Facebook such as
Zynga Poker,
YoVille, and
FarmVille.
Point being, EA absolutely wasn't the industry leader on this. Rather, they saw where the industry was going and went with that flow, just like literally every other AAA publisher has at this point.