Can I wait for this job repair?

I received a rebuilt engine that had a year warranty. The year is up and i went to to the independent shop that replaced the part. I was told I needed a transmission filter and fluid exchange which would cost me about 800. This is for a toy 2011 rav 4. I had a transmission flush @ +160. Current milage is 180k..My question is could repair wait or is it emergent?