Sunnah to recite surah yaseen in day and night

Assalamualaikum It is reported … that Ibn 'Abbas said: "Whomsoever recites Ya-Sin in the morning will be given an easy day until the evening, and whomsoever recites it in the beginning of the night will be given an easy night until the morning." [Musnad al-Darimi no. 3462] This narration according to many shuyukh is hasan, the only narrator some people disagree upon is shahr bin hawshab but the Majority of the Muhaddithin declared him reliable. Theres a principle i heard, if a companion narrates a virtue of the quran then its sunnah because he must have heard it directly from the prophet. If this is so, does this mean reciting surah yaseen in the morning and the night is a sunnah? I just wanted to confirm this belief.