While I very much doubt if the entire process is going to be carbon negative, "straight up lie" is very strongly worded. In essence, by building wooden structures you can store CO2 in urban environments that are currently dominated by concrete. To be sure, to be carbon negative the whole process needs proper thought; the trees for the wood of course needs to be replanted and the energy used in milling, construction and transportation need to be sourced durable, I get that.

But I mean, if we want anything to be carbon negative we need to capture carbon from the atmosphere and put it somewhere; e.g. reclaiming land for forests or putting carbon back into the ground where we got it from, but putting carbon in constructions as part of the solution, why not? For dealing with climate change, the important part is getting it out of the atmosphere.