Only if the packet (frame plus overhead) exceeds 9000 -
Just because host MTU is set to 9000 it does not neccessarily mean it actually sends/builds packets of this size. At same time, you do bring up a very valid point that MTU sizes should be set the same throughout the path or there is likelihood of potential packet drops. The real solution for this is the use of Path MTU Discovery (PMTUD - RFC 1191 for IPv4).
https://en.wikipedia.org/wiki/Path_MTU_Discovery