As of now the DOJ proposed bumpstock regulations do not seem to include binary triggers. When the bumpstock ban was in the initial stages of proposal there was mention of "any devices that could increase the rate of fire of a semi-automatic rifle", but I do not see that provision listed anywhere in the 55-page bumpstock ban proposal.
However, BATFE can and has declared items their Tech Branch has previously reviewed and approved (and issued 'Approval Letters' to the product designers), they have sometimes declared those items as restricted or illegal to own. Because of that precedence there is the possibility that they could at anytime regulate the binary triggers out of existence.
Currently it is my opinion that the binary triggers remain legal because BATFE would once again have to change the definition of a machine gun. Currently a legal semi-automatic shoots one round for each "function" of the trigger. In the case of the binary trigger, one function is the pull, and another function is the release of the trigger, which follows BATFE rules for a legal semi-automatic.