I’ve never heard an encore at the Met either.
Are there ever encores in European opera theaters?
I just thought I’s google my question and found this:
http://www.cbc.ca/arts/theatre/story/2007/02/23/la-scala-encore.html
Seems as tho he has done it before!
On that google page, further down, Toscannini banned encores back in 1921.
ML/NJ