Does this really erase T3 from the canon?
I don't see how. It takes place after Judgement Day. They could've easily fit it into the canon.
shareIt actually erases T1/2 as well!
it was basically similar to StarTrek 2009 but that established(more off screen than on) that the original timeline was left intact
At the time TG was promoted as the 'real T3' (Cameron even said that in an interview) however now after Dark Fate becoming the new 'real T3' (Hamilton returning, Camerons official involvement, continuing on from T2 directly) TG sort of exists in its own alternate reality separate to the rest - an 'exile in the timeline' (like the 3 JJ Trek films), and T3/4 have been erased from the 'official' timeline of T1/2/DF