During the Nintendo Switch reveal we saw Bethesda's ever-popular Skyrim running on the upcoming console, but Bethesda was quick to assert that they haven't officially confirmed the game for Nintendo Switch. That said, we suspect that it's coming to the console (and that Bethesda is simply playing coy until Nintendo's next big Switch presentation), and according to Laura Dale of Let's Play Video games, we can expect it on day one.
Dale's latest Nintendo Switch leak states that Skyrim will be a launch title that mirrors the recently-released remastered version of the game. Mods will not be supported on day one, but they are planned at some point post-launch. However, they'll apparently be limited to in-game assets, much like the PlayStation 4 version.
This information is not officially confirmed by Nintendo at this time, but one of Dale's sources is a Nintendo employee who has previously proven accurate by leaking when the Switch reveal would take place, the content of the reveal, Switch's use of cartridges, and more.
Source: Let's Play Video Games