That's not what I see from my game at least. Whenever I've done this, I'm not seeing the grass grow back at all and it's not close to any of my building structures. This had made me give up building a base in these areas when that happened as the only way to get grass and weeds over to an island (Rash island specifically), I'd have to build a zipline to there. I ended up not opting to do that, but would've liked to have built a cool house around that area. It was my fault for reading an out of date information about how grass regrows, which the person said it would only grow if you cut the stump down, but later found out that it was the case in the early Game Preview state.