Does /s/ have meaning?

I googled it and what I could find was that /s/ is used as a way to show that it’s an authorized electronic signature. That way the document can remain electronic and still be official. So technically your original assumption is wrong, but you’re pretty much there!

Yes you are right but I believe it is falling out of use. Of course this kind of thing takes a long time to change but in my office we no longer put that on electronic copies. For example if you use Microsoft Word right now and digitally sign a document, it doesn't even put a visible signature into the document. So what we do is put a signature line for the signing official to fill out their name and the date, as in the following:

Date: October 22, 2020

Signed: Joseph Conrad

I should point out that that is what you see in the original not a copy. There is some history here in terms of digital copies of documents. For a while our office was putting an actual image of the person's signature into the document. I think we were following practices in the industry at the time, about 10 years ago. This image of the signature would appear in the original as well as any digital copies or printed copies for that matter or even if we printed out the original now that I think of it. But things are evolving.

With just one slash at end of statement "/s", it means sarcasm.