Is soil coming off or looking like it might?

Yes, the soil has slowly came off during the last 10 years or so (we just moved in), right now there's a section the soil is leveling with my side walk. I would say the soil erosion is minor.

With not seeing the site or knowing your soil profile, I would error on the side of safety and install the jute netting.
The myroporum is not going to provide any sufficient upper range root matting control for a while.

If Cal Trans is any indication in regards to preparing for the upcoming rainy season , in my area you can see them out in full force applying jute netting on open and newly cut hillsides.

Seems like a pretty small investment for what could potentially be a big cost benefit if we get a lot of rain and your soil surface area is loose.
It can even mitigate a 'minor' amount of subsurface erosion by keeping the top layer intact if there is a minor sub surface slide.
In a moderate to big slide, no amount of jute is going to help.