A "recall" has to be reported to NHTSA in the US and relevant agencies in Europe(I think there's one for every country but I don't really know).
It's all public and easily searchable. It's a crime to conceal a safety issue, and Zero would be sued. Remember the Pinto?
Zero and all other auto manufacturers also do Technical Safety Bulletins for non safety related issues the manufacturer discovers. Zero does send notice of these to dealers, and pays for these. They also usually contact owners if your ownership is registered with them. The 2013/2104 Monolith Upgrade Campaign, and many others, fall into this category. I think you also have to report these to NHTSA, but they're harder to find.
If you want to know if your bike is impacted, you can always call with the VIN and ask them.
So AutoE either has evidence that Zero has a safety problem that could be a recall or he has nothing. Considering there are hundreds of other dealers in the US and EU, and not one has spoken out, I lean towards nothing.