1. Diffraction not only considers the generation of wavelets (direction problem), but also considers the superposition of these wavelets (intensity problem). That is, there is actually a diffraction problem when propagating in a straight line, but in the direction of deviation. After the superposition of all wavelets, the intensity is 0. This is the simple understanding. For slightly more detailed calculations, please refer to Feynman's physics lecture notes

2. Therefore, both laser and sunlight can be considered to have diffraction during the transmission process. Your question has little to do with whether it is a laser.