Do you think the Tree Of Harmony would do something if Celestia somehow turned evil?

[Unity 332]

If Celestia were to say, fully embrace Daybreaker, and if she somehow, became evil.

Do you think that the Tree Of Harmony would strip her of her power?

[Quinch 1,119]

Probably not - she used to be a bearer of the elements, but her powers, namely the whole sun-raising thing, aren't really connected to them.

[Twilight Luna 30,952]

Celestia no longer has any connection to the elements. That's probably why they turned to stone after Nightmare Moon was banished. 

[Ganondox 899]

Well, it would eventually, just as it ultimately was responsible for Luna's banishment, but the mane 6 would probably have to help it. 

[Cwanky 17,459]

At the very least it may take away her ability to raise the sun, considering her power seems to have originated from the tree.