Chanucah concealed light revealed The Rokeiach explains (in Hilchos Chanukah 225). The explanation is that when the Gemara says that the light was reserved. It doesn’t solely refer to the era of Moshiach. “for the tzaddikim of the future” means the or haganuz, the concealed light, becomes revealed every year when Jews light Chanukah lecht.

Regarding Chanucah concealed light revealed, the Rokeiach writes: “Chanukah we light thirty-six candles. This because by Creation…Adam HaRishon enjoyed this light for thirty-six hours: Twelve hours on Friday, twelve hours Friday night, and twelve hours on Shabbos day… A hint that the light of Creation shone for thirty-six hours is, “Hashem saw the light [of Creation] that it is good…” and on the Hebrew letter TES for NINE there are four crowns, hinting to 4 x 9 = 36. This represents the thirty-six hours [when the or haganuz shone] and to the thirty-six lights of Chanukah lecht.”

So we see from the Rokeiach that the or haganuz, the concealed light of Creation, shines (at least somewhat) when we light the Chanukah lecht.

As the Bnei Yissaschar (2:21) writes,
“Behold I have brought before you three reliable testimonies that the light of the Chanukah lecht is associated with the or haganuz:
1. The Rokeiach — whose lessons come from Eliyahu HaNavi z’l;
2 The Maharal of Prague as known, his lessons were said with ruach hakodesh and that he used Sefer Yetzirah;
3. From the holy rav, closer to our generation, renowned for his ruach hakodesh hakodesh, Reb Pinchas of Koritz zt’l