If you invest in GM do you get free cars?
The group has invested in the company to make that investment grow, not to provide a product.
Anyway, back on topic...
You are correct in thinking that Espargaro is hoping it will lead to a better Yamaha ride. With Aprilia, it's not expected to become a "factory" (Repsol Honda) level ride any time soon. Hayden doesn't have to think long term at this point though, and I expect that the Aprilia will be able to finish perhaps even better in the next season. Ducati looks like they're not making any meaningful progress, and the Ape is actually starting to outqualify them - and they haven't improved it yet. It's also looking like Aprilia may be scaling their WSBK efforts back and moving more toward MotoGP, which means more development. It could be a really good bike next year, and the Yamaha is a complete unknown.
I read somewhere (think MCN) that Forward Racings Yamaha is going to be last years satellite Yamaha Crutchlow rode.