The snapshot won't exist on ESXi host if you use converter. I don't think there is a way to import a vm to another platform and preserve an existing snapshot (see reason 2).
Scenario 1: Install Converter inside the virtual machine with a snapshot.
Converter treats it like a physical machine and converts the system "as is". It doesn't know that there is a snapshot.
Scenario 2: Running VMware Converter against the VMX file.
The resulting Parent VMDK will have been modified when the conversion is done, and this would implicitly invalidate the shapshot. A snapshot relies on the integrity of the parent disk, kinda like running an MD5 hash against it to ensure NOTHING has changed. Converter completely changes the structure of the parent disk, so a snapshot doesn't like it that way. So it includes it in the conversion.
