You've read the transfiguration story right?

What if moses and elijah did not actually 'appear' to Jesus during the transfiguration.
What if it was the other way round. ie Jesus appearing to Moses and Elijah

What if in the transfiguration experience, the disciples were actually able to glimpse what happened in the past?
ie Jesus appearing to Moses in the mountains, and Jesus appearing to Elijah ages ago

What if that is what really happened, no ghosts of dead saints appearing on this earth, just a glimpse into the past or probably into some unknown heavenly realm?

Just what if?

It could have been possible , but for the fact that the bible says so.

Mark 9:4
And there appeared unto them Elias with Moses: and they were talking with Jesus.

I believe if they had been the one translated to heaven it would have been stated , just like the translation of Paul into the third heaven in 2cor 12

Uhm
great contribution