My insider preview is tied to my old account

"it isn't connected to the Xbox account that is logged on to the xbox, but tied to the hardware"

True, to my understanding, but after the console is factory reset and reinitializes with an account to complete any updates, even if the console updates to an Insider preview, all thats required is to download the Insider Hub from the Store, run it and remove the console from any preview it may have been in.

Once you remove the console, using the Insider Hub, from a preview it will reset once again, and should be on the GA release OS for Xbox.

You will need your account info.

my account was tied to my old phone number i don't have access to anymore

oh and yeah i also have the old phone number that is on the microsoft account still tied as a secondary number on my gmail account, that also being the original gmail of the microsoft account, there is no way that is not enough proof.

My account was accepted in to preview program I just can't registermy console with my new account cause old account(banned account) is registered with preview program

You can unregister your console via the Insider app

I did but when I call Xbox support they tell me that my account is still in

preview program but my Xbox isn't so they said to unroll my account out of preview program

A me too post - Mahjong can sign in on WIndows 10 Pro Insider Preview Build 10074 on my desktop, but when I try to sign in on the WIndows 10 Home Insider Preview build 10074 on my Surface3, it fails. A white box tells me to go through the account settings
to set the account or uninstall and reinstall the game (I did that - same effect).