From Wikipedia:

In November 2022, Gearbox Entertainment acquired the Risk of Rain IP. Hopoo Games remains an independent studio. Hopoo now states that they are working on other games and projects.

The Steam page for the DLC also lists Gearbox Software as the developer and Gearbox Publishing as the publisher so yeah. Seems accurate.

ROCK AND STONE TO THE BONE!

One reason I’m glad to be a pretty broke parent gamer. I can only afford to spend money on games a couple times a year at best so I have to be really patient and picky about what I do decide to buy. I end up having no choice but to wait a year or more to pick up any games I’m excited about.