The Imperial Palace gardens were opened to the public recently to celebrate the Emperor's 80th birthday. Can someone confirm the use of the passive voice in the following sentence on the subject in context of using the passive form to show respect and addressing the Emperor?(see note below).
この特別公開は、天皇陛下が昨年12月23日に80歳の傘寿を迎えられた記念として実施されたもの。
Or, in other words, is the passive voice used here to show respect to the Emperor and aren't people supposed to use more elevated language to refer to his activities, or at least お迎えになる which I think is more honorific than the passive?
Note: example of normal use of 迎える:20歳の誕生日を迎える=celebrate one's twentieth birthday