All Honor will be converted to gold when Dragonflight releases on November 28. Therefore, do not forget to convert it to Marks of Honor!

Head to Purveyor Zo’kuul in Oribos (35, 58) and buy Orboreal Distinguishment for 2,000 Honor each. The chest gives you 5 Marks of Honor, which you can spend on transmog. The conversion occurs with the release of Dragonflight and you will only receive a small amount of gold. 

Valor and Conquest will also reset on November 28.