Bear in mind that Mauna Kea is only one of two excellent locations in the northern hemisphere... the other being Gran Canarias in the Atlantic. Chile is equally as good as Hawaii with stable ocean air and dry conditions making for fantastic seeing conditions, but it covers a very different part of the night sky down south.

I can’t imagine UH doing what the protectors are asking and simply plonk the TMT in a completely different ocean.

TMT is the only planned 30m class telescope in the northern hemisphere at the moment.

Longitudinal placement is also important for tracking transient phenomena such as FRB’s and NEO’s. this is why Hawaii is such a critical location for doing optical observations.

I would not be surprised if the Chinese build a thirty meter class telescope at some stage. Not sure where though?