Yup. Even with the necessary changes for the 3DS, the remasters adhere to the original concept art. I never understood the complaints that they 'Disney-fied' the graphics. Even the original game looks bright and saturated when played on a CRT with its natural bloom and color.
If an 'HD port' of the 3DS version were to happen, it would need more work put into it. The 3D version has a decreased FOV, and character models and textures are detailed for the 240p handheld screen. Even with an HD texture pack in Citra, the visuals are blocky and zoomed in when you play in 1080p. This was a home console game crammed into a handheld, and Ocarina was always intended as a grand experience. If they re-release it, I don't want it to feel like I'm emulating it on Citra.
They might use Grezzo's models as a base, but the result would probably end up like TP/WW/SS HD where they did end up expanding the camera and touching up character models. Though I would love a Prime Remastered level of visual remake with adjusted lighting.