Official document for validating the creation of account "VMware_Conv_SA" being created automatically when vCenter Converter Standalone is installed/used.
Please suggest.
Don't understand what you're asking.
It is not in the guide or release notes because this is an internal implementation detail, i.e. not documented.
Otherwise - yes, Converter creates its own user account when installed. Its name is "___VMware_Conv_SA___", a little different from what you write.
I don't know from what point of view the question is. If it is from a technical, I am a Converter developer, so perhaps this is official enough; if it is from a legal PoV, then it is not official.
HTH,
Plamen