@lukas no, its exactly the opposite, I dont think you understood what was written in the blog. Like @DriNeo said, its good to have one big texture to act as a sprite sheet, and then draw parts of it. Its not good to have big-ass textures to use as a "map of a whole level".
So, you would use a big texture with all kinds of sprites used in that level, and draw them as necessary. The sprite texture would only be loaded into memory once and then parts of it used when necessary. With this you avoid the loading/unloading of different textures