At a quick initial glance, in some ways the final version of the tax bill makes the gaming potential of the passthrough rules even greater than before. For example, they have expanded the ability of partnerships et al that can jam some property ownership into the business to claim large tax benefits even without having many employees.
They've also decided that architects and engineers, unlike all the other "personal service business" types such as doctors and lawyers, can now get full benefits from the rule. The arbitrariness of this exclusion helps to underscore how corrupt and unprincipled the entire process of developing this legislation in general, and the passthrough rules as a particular example, has been. This truly is incoherent industrial policy, reflecting fundamental disrespect for a free market economy, as well as for neutrality, transparency, and public oversight.
On the bright side for lawyers, there will be millions of dollars in legal fees devoted to devising and implementing brand new tax avoidance strategies (and not just in the pass-throughs rules, of course). Law firms are going to need to hire additional tax lawyers to work on all this.