Gives Bill some added optionality. Kendricks is clearly on the bubble, and so if he was likely going to be cut anyway, then Bill will cut him a week later and no harm done. But this way if we get another TE injury, then maybe Bill has a chance to add Kendricks for game 2. If he was probably going to be on the roster, then also no harm done. We get an extra player for week 1, and then depending on injuries and performance you cut or IR some other player and add Kendricks.
Edit: And in the latter case, his salary is no longer guaranteed, so if some "other" TE were to return later in the year...