Season of Master Quetion:

[Asma-bloodsail-buccaneers]

That is not a possibility that has been offered. We only have this from Blizzard:

@Kaivax

Looking Forward

Finally, many Classic players have asked what will happen at the end of the Season of Mastery, and here’s the answer. When Season of Mastery concludes, you’ll have the option to permanently transfer your character to an existing Classic Era realm in your region. This free service will become available for a limited time at the conclusion of the season.
While we don’t yet know the exact destination realm and specific dates, you’ll have plenty of time to move your character to a safe home before all Season of Mastery realms are permanently closed.

Nothing about moving to TBC Classic. Sorry.
Currently the only Era characters that can “move” to TBC are those present at the time of the cloning in TBC prepatch.