The manufacturer loved this tape and it is pretty much standard under most of the later rigs. It's not to fix a mistake or repair something broken that anyone has reported - seems to be holding up wiring and such. Over on the Zion/Simplicity Facebook page is the place to find out exactly why it might be on there. To be honest, I never looked underneath to see if mine has it.
As to warranty, I believe that Rapido/Roadtrek Inc only put their limited 2 year warranty on rigs sold before a particular date. They assumed that those sold after had the lack of warranty reflected in lower prices. My warranty ends this July and they have only had to pay one claim to replace my underhood generator. (which was installed with the wrong controller) You would need to touch base with their warranty department and give them the vin to confirm any coverage. But, of course, the factory is still closed due to the virus.