While I personally find it unlikely, as the connection between the EtG weapon and the Stand seems rather tenuous, I thought it would be worth mentioning that it's not impossible for this weapon's name to be a JoJo reference.
While the dubbed version of Vento Aureo only recently started production, the Stand Aerosmith would first receive its localized name "Li'l Bomber" in the PS3 video game, JoJo's Bizarre Adventure: All Star Battle. This game would be released in the Americas, and thus feature the localized names, in April 2014, two years before the initial release of Enter the Gungeon.
Again, I personally find the idea that the EtG weapon is named after the Stand to be implausible, but I'll leave the final decision on whether the trivia entry goes or stays to people with more authority around here.
- Did not know about the video game thing. Even still, I find it really unlikely that this is a jojo reference. All aspects of the gun reference Bomberman, and I think its pretty safe to say that was its inspiration, especially since the gun functions nothing like Aerosmith.