I love the Discover Weekly playlist and try to interact with the Like and Don't Like buttons as much as possible to better inform the Spotify Algorithms. It is slightly annoying, however, that the "Like" button is the same button that can be found on any song which will add it to your "Liked Songs" playlist. It would be better if you could go through and react to each song in your discover weekly to indicate if you like it or not without that affecting your playlists.
As it stands, I withhold from "Liking" some songs that I would want Spotify to continue suggesting in my Discover Weekly as I don't want them to appear in my "Liked Songs' playlist which I listen to somewhat frequently.
My suggestion would be for a slight improvement to the Discover Weekly liking and disliking system such that this is a stand alone system with no impact other than informing suggested sogs for your Discover Weekly playlist.