Does Irelia's triggered ability with a 'may' clause count as an optional cost that interacts with Ezreal, Prodigy's cost reduction?

Ruling: Irelia's ability is not an optional additional cost and does not interact with Ezreal, Prodigy's cost reduction. Only costs that explicitly include both "may" and "as an additional cost" qualify as optional additional costs.

Nuances:

• The ability is optional (contains "may") and is a cost ("Do X To Y" structure), but it is not an "additional" cost
• Ezreal specifically reduces "optional additional costs," not all optional costs
• The distinction requires both the optional nature ("may") AND the "as an additional cost" wording to qualify