Is it normal to have a 'Can't keep up' event on reload?

I am currently setting-up a Minecraft server on a VPS. For the most part, the server is brilliant and does not have any lag (with one player online, the entire VPS only uses 0.4% CPU [reported by top]).

However when I trigger a reload (using /reload ingame), I am kicked after around ten seconds and a Can't keep up! event is recorded in the log:

[18:52:56] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 33664ms behind, skipping 673 tick(s)

Since the Minecraft server is running Craftbukkit with many plugins (such as WorldEdit & Factions), is overloading expected on a /reload (I'm sure it's expected behaviour, but I wanted to double-check)?

The VPS has 16 CPU cores (Intel Xeon E5550), 30GB RAM, and 800GB HDD (aka, more than enough), on Ubuntu 14.04. There are other programs hosted on the VPS such as a MySQL server, Apache2, and Teamspeak3 (I plan to move the webserver & MySQL server to a standalone server as soon as I'm in the position financially to do so). Other programs are not stealing resources.

This is the server's startup line, enabling use of all cores on the VPS & using 27GB of RAM (leaving only 3GB for the OS & other programs):

java -jar -d64 -XX:MaxPermSize=512M -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=16 -XX:+AggressiveOpts -Xms8G -Xmx27G /games/minecraft/minecraft-server.jar

The Minecraft is set to start-up on boot via a screen session executing the above startup line, in rc.init.

Is this behavior expected of a server that is reloading?