According to some, Moshe received the torah in its entirety, including all that is d'rabanan.
Avrohum followed the entire torah. Yosef's brothers even followed the entire torah (re: yosef complaint of Aver Min Hachai). That means Moses, Our Teacher, kept the rules of Sfira. He did not get a haircut during the 33 days nor did he listen to music. He was privy to the information that some day in the future R' Akivas students will perish because they did not respect each other.
Why then didn't Moe pass on a note to future generations, to R Akiva, to teach all incoming students to love thy neighbor?
Why didn't Avrohom, Our Father, who already was keeping pesach, inform the Jews that they would be saved by a dude named Moses...you know, THE SECOND IN COMMAND OF EGYPT? That should have really been a known secret.
Why didn't Aaron, The Priest, leave a sticky note that read:
Save yourself the trouble and knock off Haman while he is still an infant.
Why didn't Yosef, The Righteous, warn Jews of Temple 1 and Temple 2 eras to amass a large army leading up to the 9th of Av and to look out for a dude named Nevuchadnetzar or Titus?
Side note: DovBear needs a descriptive title. How about DovBear, The Verbal?