Not that this helps the Romans any. The Goths were giving trouble over a century before the Huns came along, and these Goths will have gunpowder weapons.
In OTL, gunpowder was the reason settled civilizations finally gained an advantage over their barbarian neighbors. Before gunpowder, the military balance is in a see saw, with civilized societies having difficulty beating their less civilized neighbors, and in fact, they lost more often than not. After gunpowder, the balance swung decisively the other way, despite some exceptions. The best exception, of course, is the Manchu conquest of the Ming. But that was an outlier, and an exception to the rule.
In OTL, nomads and barbarians, after the 1600s, with a few exceptions, were not able to compete with civilized urban societies in warfare.
So why would Rome and its northern neighbors be any different?
Why would the Germanic tribes have gunpowder weapons? Gunpowder societies needed a civilized urban society to sustain such an army.That is why I think that gunpowder weapons would be a gamechanger. I simply cannot imagine that the GErmans north of the Danube or east of the Rhine can set up a society that could manufacture huge amounts of gunpowder, muskets, bullets, cannon, cannon balls, artillery, etc. unless they fundamentally changed their societies, which would make them even easier to conquer for the Romans.
I mean, can you tell me a nomadic society in OTL, from its own internal sources, that were able to create a manufacture and create gunpowder weapons in sufficient quantities to beat a settle, civilized, gunpowder empire larger than itself many times over?
The reasons the Germans in OTL can defeat Rome is because the weapons of the Romans and the Germans are of comparable technology. Swords, bows, shields, and arrows are relatively easy to manufacture in comparison with cannons, muskets, gunpowder, etc. If the Germans want to manufacture these things in quantity, then they have to develop urban centers.
Yet that would mean that the Romans would have something to capture in their wars against them, like how the Romans used the fact the Gauls have oppidums and other fixed settled places to be able to conquer it, etc. It was argued that the reason Germania was so hard to conquer was that there were no fixed places to capture and occupy. Now, with gunpowder, the Germans would need to create such fixed settlements in order to manufacture gunpowder, etc.