Mashiach: Each Our Own Lag B’omer
It is like the resurrection of the dead.
When Mashiach comes (very soon) we will all have our own hilula, our own “wedding” with Hashem, our own resurrection of the dead.
Why the bonfire?
Rabbi Shimon reached the level of Mashiach. The “skin of the snake” fell off, the “garments of skin”, and he received his “garments of Light” like Adam before the sin. (Not physical light, of course.) There is a “garment of Light” waiting for you and me, too. Soon our “skin of the snake/garments of skin” will too fall off, replaced by our Divine “garment of Light”, and we will also have our own Lag B’omer to celebrate, along with our own bonfire!
Perhaps this explains the custom of the holy tzaddik the Ohr Hachayim: on Lag B’omer he would throw expensive garments into the burning bonfire. Shedding the skin of the snake and accepting the garments of Divine Light!