Wouldn't bet on it right now, the gov't isn't fond of giving up taxable income, that $200 tax stamp was set back when most people didn't bring home $200 in 6 months
The $200 stamp is a drop in the bucket. That revenue isn't important, is it was they'd be requiring suppressors and automating the process so you got one in an hour. They make a couple of hundred million on tax stamps... probably not even the NFA division's budget.
This is politics, and if the political stars align this will go through while everyone is looking at the SC nomination or the first brick laid in the Mexican wall.
My only real concern is that the NRA will push the whole national reciprocity fiasco over this. That will NEVER pass and the political capital it loses will be the end of any pro-gun push the Trumps try to get through.