I don’t think it is a stretch for people to believe a temperate moon like Endor has grasslands across the coastlines. Naboo has swamps and pastures, it isn’t a completely homogenous climate. I also figured most people assumed that as soon as we saw the Death Star wreckage in the trailer, that it was Endor. I think having a transition shot like that is enough to show the audience that it’s Endor.
The cinematic masterpiece that is Caravan of Courage: An Ewok Adventure didn’t think it was too much of a stretch.