If I am following you correctly, most people who call themselves Christian would probably disagree with the concept of 'universal salvation' ... few would claim that EVERYONE is saved and going to heaven.
Through Jesus, everyone has access to forgiveness, but confession and repentance are generally viewed as the personal cost of obtaining that forgiveness.
First one must consider what salvation might be. And how it might be obtained.
it is generally understood that salvation can not be earned but comes through the grace of God.
Salvation is a process.
Most will believe that sin is only forgiven following repentance, confession is not part of the equation but might help one understand what to repent.
When does This take place? Certainly not when we are alive.
Salvation is not a thing, nor is it a promise. Nor can it be earned. What ever we believe it to be, it can only be expressed in the presence and fullness of God.
Nor is Salvation a continuation of this life on earth or a second physical life on a new earth.
It can only lead to a spiritual existance.
From my understanding Salvation is our souls return to God, with our sins and egos cleansed.
This cleansing and return is inevitable.
What happens next?
There seems to be three alternatives, Firstly we might remain one with God.
Secondly God might have further plans or tasks for us. Or Thirdly our very cleansing might have reduced our souls to nothing.
I believe in neither heaven nor Hell as places. Nor do I believe in a physical resurrection.
The process of Salvation happens to every one Christian or not, good or bad. In that regard it is universal.