This is, of course, pure supposition but it would make sense if they were to set building up in such a way that you could dismantle the starting framework of any structure so misplaced bits could be cleared away. They could have you set up a cheaper frame, rather than the full priced item, that might cost 1 plank. Afterward you would utilize wooden planks in a way similar to using wood to repair a wooden structure, and they might have it set up so that one person could add one wood plank every so often making larger groups able to build faster than a single person.
It remains to be seen what, exactly, the plans are of course. Still, I’d say my guess has the merit of solving something that is in need of a solution (dismantling accidental placement of items) as well as preventing easy griefing by players. Of course, a concerted effort to grief other people would still be viable, as well as building structures for the specific purpose of griefing when the owners of a base weren’t online. Still, it would require additional time and trouble, and could potential be a noisy prospect where current building is completely silent and instantaneous. This way if you were in your base and someone started to build a staircase to your roof, it would give you time to prepare a proper welcoming party for your uninvited guests.