The towing hitch is coming as an accessory soon:
https://gmauthority.com/blog/2020/07/heres-how-to-tow-with-the-2021-trailblazer/
In fact, it might already be available to order.
Here’s a thread about the roof rack cross bars:
https://gmauthority.com/blog/topic/2021-trailblazer-crossbars/
I have been in direct contact with Chevrolet about the cross bars, and the status on them is unclear:
https://gmauthority.com/blog/2020/07/2021-chevy-trailblazer-roof-rack-cross-bars-are-nowhere-to-be-found/
