Roscosmos' statement also outlines a rough plan to create a set of international technical standards for the lunar space station and beyond. Specifically, both docking ports and life support systems will be based on Russian design; after all, they have a lot more experience running a space station and the current life support systems aboard the ISS are in the Russian section, Zvezda.
Right now, the ISS has different ports for the multiple vehicles that dock with it. The Russian Soyuz capsule uses a different style docking port than the Space Shuttle did -- the Americans had to install adapters to convert Shuttle docking ports and allow private craft like SpaceX's Dragon to connect with them. Collaboration from the ground up, rather than making our own plans and partnering with the Russians at the last minute (like we did with the International Space Station), means that we can establish, collaborate on and coordinate technical specifications, making things easier in the medium and long term.
NASA's relying on its much-delayed heavy lift rocket, the SLS, to build the Deep Space Gateway, but they're only planning on launching it once a year. That timeline didn't seem feasible, and now Roscosmos's statement sheds some light: Russia's rockets will help out with the construction. Both agencies, as well as other ISS partners, are tasking their countries' respective industry partners with creating concept studies of what the Gateway might look like.
This is a big deal for many reasons; working together, despite political tensions, means that our countries are less likely to descend into outright hostilities. Additionally, NASA's aims have been somewhat unclear for a long time. They laid out ambitious goals without a clear plan on how they were going to achieve them, and without the budget to support them. Since then, the organization has slowly been scaling back. But now, with international agreements of cooperation, it looks like the Deep Space Gateway will happen. And because it's we have international partners, Congress will be less likely to cancel the project; after all, that's how the International Space Station scraped by with just one vote.