I am in Canada also. I just ordered a Denali with out max tow and my dealer told me max tow was on constraint rest of stuff no constraints.^^ I just placed an order (in Canada) for Z71 with max tow/Lux/2nd row buckets and my dealer advised that it did not look like any of the options were under constraint. The order has not yet been picked up, however. I was quoted 3-6 months for delivery.
I'm in a similar situation as you, I actually ordered a Land Rover Defender back in August '22 which was supposed to be delivered in December, then April '23 then August '23 so I cancelled that and ordered the Tahoe. I was upfront with my sales guy that I'll do the same if GM screws around with never ending delays and he assured me that they would know if anything was constrained and we could remove it from the build.