on the one hand, it's an act of arrogance - as though the american senate gets to write history. i mean, on that level, it's absurd. if they repeal the vote, does that mean they can erase history, too?
but, it's really a political message to the turks that their days in the western alliance are numbered. for, there's only one reason it took 100 years to do this - because we didn't want to upset our turkish allies.
that said, there's an argument that it's kind of unnecessarily provocative, with little real purpose or value. i mean, nobody cares if the united states senate thinks a genocide happened in armenia or not - it's not an argument, it's not evidence, etc. if some academic somewhere changes their position on this, please let me know who they are so i can ridicule them in this space for the next twenty years. it's just intended to piss them off; there's no other reason to do it. and, that might not be the best way to deal with the substantive differences arising between the turks and the increasingly saudi-aligned americans.
in that sense, it's nearly a declaration of war. but, i don't think it's intended that way - it's intended to be an act of supremacy, to put the turks in their place, and is coming off more like a delusion of arrogance.
the turks may not react immediately. but, it's bound to fester, and, in the end, is likely to just end up unhelpful.
but, i'd encourage you to consult historians for history, and not the results of votes passed in the legislative bodies of representative democracies.